From 1db40393515c9b8c0286ab2cea8d8b05b831286c Mon Sep 17 00:00:00 2001
From: Yu ISHIKAWA <yuu.ishikawa@gmail.com>
Date: Tue, 25 Aug 2015 15:00:55 +0900
Subject: [PATCH 1/5] Add `@name` to each methods  and modify `@aliases` in
 DataFrame.R

---
 R/pkg/R/DataFrame.R | 83 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 68 insertions(+), 15 deletions(-)

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index 895603235011e..19417be0c53b4 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -27,6 +27,7 @@ setOldClass("jobj")
 #'              \code{jsonFile}, \code{table} etc.
 #' @rdname DataFrame
 #' @seealso jsonFile, table
+#' @docType class
 #'
 #' @param env An R environment that stores bookkeeping states of the DataFrame
 #' @param sdf A Java object reference to the backing Scala DataFrame
@@ -84,6 +85,7 @@ setMethod("printSchema",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname schema
+#' @name schema
 #' @export
 #' @examples
 #'\dontrun{
@@ -106,6 +108,7 @@ setMethod("schema",
 #' @param x A SparkSQL DataFrame
 #' @param extended Logical. If extended is False, explain() only prints the physical plan.
 #' @rdname explain
+#' @name explain
 #' @export
 #' @examples
 #'\dontrun{
@@ -135,6 +138,7 @@ setMethod("explain",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname isLocal
+#' @name isLocal
 #' @export
 #' @examples
 #'\dontrun{
@@ -158,6 +162,7 @@ setMethod("isLocal",
 #' @param numRows The number of rows to print. Defaults to 20.
 #'
 #' @rdname showDF
+#' @name showDF
 #' @export
 #' @examples
 #'\dontrun{
@@ -206,6 +211,7 @@ setMethod("show", "DataFrame",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname dtypes
+#' @name dtypes
 #' @export
 #' @examples
 #'\dontrun{
@@ -230,6 +236,8 @@ setMethod("dtypes",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname columns
+#' @name columns
+#' @aliases names
 #' @export
 #' @examples
 #'\dontrun{
@@ -248,7 +256,7 @@ setMethod("columns",
           })
 
 #' @rdname columns
-#' @aliases names,DataFrame,function-method
+#' @name names
 setMethod("names",
           signature(x = "DataFrame"),
           function(x) {
@@ -256,6 +264,7 @@ setMethod("names",
           })
 
 #' @rdname columns
+#' @name names<-
 setMethod("names<-",
           signature(x = "DataFrame"),
           function(x, value) {
@@ -273,6 +282,7 @@ setMethod("names<-",
 #' @param tableName A character vector containing the name of the table
 #'
 #' @rdname registerTempTable
+#' @name registerTempTable
 #' @export
 #' @examples
 #'\dontrun{
@@ -299,6 +309,7 @@ setMethod("registerTempTable",
 #' the existing rows in the table.
 #'
 #' @rdname insertInto
+#' @name insertInto
 #' @export
 #' @examples
 #'\dontrun{
@@ -347,6 +358,7 @@ setMethod("cache",
 #'
 #' @param x The DataFrame to persist
 #' @rdname persist
+#' @name persist
 #' @export
 #' @examples
 #'\dontrun{
@@ -372,6 +384,7 @@ setMethod("persist",
 #' @param x The DataFrame to unpersist
 #' @param blocking Whether to block until all blocks are deleted
 #' @rdname unpersist-methods
+#' @name unpersist
 #' @export
 #' @examples
 #'\dontrun{
@@ -397,6 +410,7 @@ setMethod("unpersist",
 #' @param x A SparkSQL DataFrame
 #' @param numPartitions The number of partitions to use.
 #' @rdname repartition
+#' @name repartition
 #' @export
 #' @examples
 #'\dontrun{
@@ -446,6 +460,7 @@ setMethod("toJSON",
 #' @param x A SparkSQL DataFrame
 #' @param path The directory where the file is saved
 #' @rdname saveAsParquetFile
+#' @name saveAsParquetFile
 #' @export
 #' @examples
 #'\dontrun{
@@ -467,6 +482,7 @@ setMethod("saveAsParquetFile",
 #'
 #' @param x A SparkSQL DataFrame
 #' @rdname distinct
+#' @name distinct
 #' @export
 #' @examples
 #'\dontrun{
@@ -488,7 +504,8 @@ setMethod("distinct",
 #' @description Returns a new DataFrame containing distinct rows in this DataFrame
 #'
 #' @rdname unique
-#' @aliases unique
+#' @name unique
+#' @aliases distinct
 setMethod("unique",
           signature(x = "DataFrame"),
           function(x) {
@@ -526,7 +543,7 @@ setMethod("sample",
           })
 
 #' @rdname sample
-#' @aliases sample
+#' @name sample_frac
 setMethod("sample_frac",
           signature(x = "DataFrame", withReplacement = "logical",
                     fraction = "numeric"),
@@ -541,6 +558,7 @@ setMethod("sample_frac",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname count
+#' @aliases nrow
 #' @export
 #' @examples
 #'\dontrun{
@@ -574,6 +592,7 @@ setMethod("nrow",
 #' @param x a SparkSQL DataFrame
 #'
 #' @rdname ncol
+#' @name ncol
 #' @export
 #' @examples
 #'\dontrun{
@@ -593,6 +612,7 @@ setMethod("ncol",
 #' @param x a SparkSQL DataFrame
 #'
 #' @rdname dim
+#' @name dim
 #' @export
 #' @examples
 #'\dontrun{
@@ -613,8 +633,8 @@ setMethod("dim",
 #' @param x A SparkSQL DataFrame
 #' @param stringsAsFactors (Optional) A logical indicating whether or not string columns
 #' should be converted to factors. FALSE by default.
-
-#' @rdname collect-methods
+#' @rdname collect
+#' @name collect
 #' @export
 #' @examples
 #'\dontrun{
@@ -650,6 +670,7 @@ setMethod("collect",
 #' @return A new DataFrame containing the number of rows specified.
 #'
 #' @rdname limit
+#' @name limit
 #' @export
 #' @examples
 #' \dontrun{
@@ -669,6 +690,7 @@ setMethod("limit",
 #' Take the first NUM rows of a DataFrame and return a the results as a data.frame
 #'
 #' @rdname take
+#' @name take
 #' @export
 #' @examples
 #'\dontrun{
@@ -696,6 +718,7 @@ setMethod("take",
 #' @return A data.frame
 #'
 #' @rdname head
+#' @name head
 #' @export
 #' @examples
 #'\dontrun{
@@ -717,6 +740,7 @@ setMethod("head",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname first
+#' @name first
 #' @export
 #' @examples
 #'\dontrun{
@@ -769,6 +793,7 @@ setMethod("toRDD",
 #' @seealso GroupedData
 #' @aliases group_by
 #' @rdname groupBy
+#' @name groupBy
 #' @export
 #' @examples
 #' \dontrun{
@@ -792,7 +817,7 @@ setMethod("groupBy",
            })
 
 #' @rdname groupBy
-#' @aliases group_by
+#' @name group_by
 setMethod("group_by",
           signature(x = "DataFrame"),
           function(x, ...) {
@@ -805,6 +830,7 @@ setMethod("group_by",
 #'
 #' @param x a DataFrame
 #' @rdname DataFrame
+#' @name agg
 #' @aliases summarize
 #' @export
 setMethod("agg",
@@ -814,7 +840,7 @@ setMethod("agg",
           })
 
 #' @rdname DataFrame
-#' @aliases agg
+#' @name summarize
 setMethod("summarize",
           signature(x = "DataFrame"),
           function(x, ...) {
@@ -890,12 +916,14 @@ getColumn <- function(x, c) {
 }
 
 #' @rdname select
+#' @name $
 setMethod("$", signature(x = "DataFrame"),
           function(x, name) {
             getColumn(x, name)
           })
 
 #' @rdname select
+#' @name $<-
 setMethod("$<-", signature(x = "DataFrame"),
           function(x, name, value) {
             stopifnot(class(value) == "Column" || is.null(value))
@@ -923,6 +951,7 @@ setMethod("$<-", signature(x = "DataFrame"),
           })
 
 #' @rdname select
+#' @name [[
 setMethod("[[", signature(x = "DataFrame"),
           function(x, i) {
             if (is.numeric(i)) {
@@ -933,6 +962,7 @@ setMethod("[[", signature(x = "DataFrame"),
           })
 
 #' @rdname select
+#' @name [
 setMethod("[", signature(x = "DataFrame", i = "missing"),
           function(x, i, j, ...) {
             if (is.numeric(j)) {
@@ -1008,6 +1038,7 @@ setMethod("select",
 #' @param ... Additional expressions
 #' @return A DataFrame
 #' @rdname selectExpr
+#' @name selectExpr
 #' @export
 #' @examples
 #'\dontrun{
@@ -1034,6 +1065,8 @@ setMethod("selectExpr",
 #' @param col A Column expression.
 #' @return A DataFrame with the new column added.
 #' @rdname withColumn
+#' @name withColumn
+#' @aliases mutate
 #' @export
 #' @examples
 #'\dontrun{
@@ -1057,7 +1090,7 @@ setMethod("withColumn",
 #' @param col a named argument of the form name = col
 #' @return A new DataFrame with the new columns added.
 #' @rdname withColumn
-#' @aliases withColumn
+#' @name mutate
 #' @export
 #' @examples
 #'\dontrun{
@@ -1094,6 +1127,7 @@ setMethod("mutate",
 #' @param newCol The new column name.
 #' @return A DataFrame with the column name changed.
 #' @rdname withColumnRenamed
+#' @name withColumnRenamed
 #' @export
 #' @examples
 #'\dontrun{
@@ -1124,6 +1158,7 @@ setMethod("withColumnRenamed",
 #' @param newCol A named pair of the form new_column_name = existing_column
 #' @return A DataFrame with the column name changed.
 #' @rdname withColumnRenamed
+#' @name rename
 #' @aliases withColumnRenamed
 #' @export
 #' @examples
@@ -1165,6 +1200,8 @@ setClassUnion("characterOrColumn", c("character", "Column"))
 #' @param ... Additional sorting fields
 #' @return A DataFrame where all elements are sorted.
 #' @rdname arrange
+#' @name arrange
+#' @aliases orderby
 #' @export
 #' @examples
 #'\dontrun{
@@ -1191,7 +1228,7 @@ setMethod("arrange",
           })
 
 #' @rdname arrange
-#' @aliases orderBy,DataFrame,function-method
+#' @name orderby
 setMethod("orderBy",
           signature(x = "DataFrame", col = "characterOrColumn"),
           function(x, col) {
@@ -1207,6 +1244,7 @@ setMethod("orderBy",
 #' or a string containing a SQL statement
 #' @return A DataFrame containing only the rows that meet the condition.
 #' @rdname filter
+#' @name filter
 #' @export
 #' @examples
 #'\dontrun{
@@ -1228,7 +1266,7 @@ setMethod("filter",
           })
 
 #' @rdname filter
-#' @aliases where,DataFrame,function-method
+#' @name where
 setMethod("where",
           signature(x = "DataFrame", condition = "characterOrColumn"),
           function(x, condition) {
@@ -1247,6 +1285,7 @@ setMethod("where",
 #' 'inner', 'outer', 'left_outer', 'right_outer', 'semijoin'. The default joinType is "inner".
 #' @return A DataFrame containing the result of the join operation.
 #' @rdname join
+#' @name join
 #' @export
 #' @examples
 #'\dontrun{
@@ -1279,8 +1318,9 @@ setMethod("join",
             dataFrame(sdf)
           })
 
-#' rdname merge
-#' aliases join
+#' @rdname merge
+#' @name merge
+#' @aliases join
 setMethod("merge",
           signature(x = "DataFrame", y = "DataFrame"),
           function(x, y, joinExpr = NULL, joinType = NULL, ...) {
@@ -1298,6 +1338,7 @@ setMethod("merge",
 #' @param y A Spark DataFrame
 #' @return A DataFrame containing the result of the union.
 #' @rdname unionAll
+#' @name unionAll
 #' @export
 #' @examples
 #'\dontrun{
@@ -1319,6 +1360,7 @@ setMethod("unionAll",
 #' @description Returns a new DataFrame containing rows of all parameters.
 #
 #' @rdname rbind
+#' @name rbind
 #' @aliases unionAll
 setMethod("rbind",
           signature(... = "DataFrame"),
@@ -1339,6 +1381,7 @@ setMethod("rbind",
 #' @param y A Spark DataFrame
 #' @return A DataFrame containing the result of the intersect.
 #' @rdname intersect
+#' @name intersect
 #' @export
 #' @examples
 #'\dontrun{
@@ -1364,6 +1407,7 @@ setMethod("intersect",
 #' @param y A Spark DataFrame
 #' @return A DataFrame containing the result of the except operation.
 #' @rdname except
+#' @name except
 #' @export
 #' @examples
 #'\dontrun{
@@ -1403,6 +1447,8 @@ setMethod("except",
 #' @param mode One of 'append', 'overwrite', 'error', 'ignore'
 #'
 #' @rdname write.df
+#' @name write.df
+#' @aliases saveDF
 #' @export
 #' @examples
 #'\dontrun{
@@ -1435,7 +1481,7 @@ setMethod("write.df",
           })
 
 #' @rdname write.df
-#' @aliases saveDF
+#' @name saveDF
 #' @export
 setMethod("saveDF",
           signature(df = "DataFrame", path = "character"),
@@ -1466,6 +1512,7 @@ setMethod("saveDF",
 #' @param mode One of 'append', 'overwrite', 'error', 'ignore'
 #'
 #' @rdname saveAsTable
+#' @name saveAsTable
 #' @export
 #' @examples
 #'\dontrun{
@@ -1505,6 +1552,7 @@ setMethod("saveAsTable",
 #' @param ... Additional expressions
 #' @return A DataFrame
 #' @rdname describe
+#' @aliases summary
 #' @export
 #' @examples
 #'\dontrun{
@@ -1538,7 +1586,7 @@ setMethod("describe",
 #' @description Computes statistics for numeric columns of the DataFrame
 #'
 #' @rdname summary
-#' @aliases describe
+#' @name summary
 setMethod("summary",
           signature(x = "DataFrame"),
           function(x) {
@@ -1562,6 +1610,8 @@ setMethod("summary",
 #' @return A DataFrame
 #'
 #' @rdname nafunctions
+#' @name dropna
+#' @aliases na.omit
 #' @export
 #' @examples
 #'\dontrun{
@@ -1588,7 +1638,8 @@ setMethod("dropna",
             dataFrame(sdf)
           })
 
-#' @aliases dropna
+#' @rdname nafunctions
+#' @name na.omit
 #' @export
 setMethod("na.omit",
           signature(x = "DataFrame"),
@@ -1615,6 +1666,7 @@ setMethod("na.omit",
 #' @return A DataFrame
 #'
 #' @rdname nafunctions
+#' @name fillna
 #' @export
 #' @examples
 #'\dontrun{
@@ -1685,6 +1737,7 @@ setMethod("fillna",
 #'         occurrences will have zero as their counts.
 #'
 #' @rdname statfunctions
+#' @name crosstab
 #' @export
 #' @examples
 #' \dontrun{

From ea771dff8af0cc4e21a21c14096531de96c20b13 Mon Sep 17 00:00:00 2001
From: Yu ISHIKAWA <yuu.ishikawa@gmail.com>
Date: Tue, 25 Aug 2015 15:02:57 +0900
Subject: [PATCH 2/5] Change `@param` to `@slot` at DataFrame class

---
 R/pkg/R/DataFrame.R | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index 19417be0c53b4..749b9d864555d 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -29,8 +29,8 @@ setOldClass("jobj")
 #' @seealso jsonFile, table
 #' @docType class
 #'
-#' @param env An R environment that stores bookkeeping states of the DataFrame
-#' @param sdf A Java object reference to the backing Scala DataFrame
+#' @slot env An R environment that stores bookkeeping states of the DataFrame
+#' @slot sdf A Java object reference to the backing Scala DataFrame
 #' @export
 setClass("DataFrame",
          slots = list(env = "environment",

From b7542c14bc81a4801ab50aed37f95b5a0b530fbb Mon Sep 17 00:00:00 2001
From: Yu ISHIKAWA <yuu.ishikawa@gmail.com>
Date: Tue, 25 Aug 2015 15:11:53 +0900
Subject: [PATCH 3/5] Modify @rdname tags and Add @name in column.R

---
 R/pkg/R/column.R | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/R/pkg/R/column.R b/R/pkg/R/column.R
index a1f50c383367c..d5dfd4525db0e 100644
--- a/R/pkg/R/column.R
+++ b/R/pkg/R/column.R
@@ -24,10 +24,9 @@ setOldClass("jobj")
 
 #' @title S4 class that represents a DataFrame column
 #' @description The column class supports unary, binary operations on DataFrame columns
-
 #' @rdname column
 #'
-#' @param jc reference to JVM DataFrame column
+#' @slot jc reference to JVM DataFrame column
 #' @export
 setClass("Column",
          slots = list(jc = "jobj"))
@@ -122,8 +121,11 @@ createMethods()
 #' alias
 #'
 #' Set a new name for a column
-
-#' @rdname column
+#'
+#' @rdname alias
+#' @name alias
+#' @family colum_func
+#' @export
 setMethod("alias",
           signature(object = "Column"),
           function(object, data) {
@@ -138,7 +140,9 @@ setMethod("alias",
 #'
 #' An expression that returns a substring.
 #'
-#' @rdname column
+#' @rdname substr
+#' @name substr
+#' @family colum_func
 #'
 #' @param start starting position
 #' @param stop ending position
@@ -152,7 +156,9 @@ setMethod("substr", signature(x = "Column"),
 #'
 #' Test if the column is between the lower bound and upper bound, inclusive.
 #'
-#' @rdname column
+#' @rdname between
+#' @name between
+#' @family colum_func
 #'
 #' @param bounds lower and upper bounds
 setMethod("between", signature(x = "Column"),
@@ -167,7 +173,9 @@ setMethod("between", signature(x = "Column"),
 
 #' Casts the column to a different data type.
 #'
-#' @rdname column
+#' @rdname cast
+#' @name cast
+#' @family colum_func
 #'
 #' @examples \dontrun{
 #'   cast(df$age, "string")
@@ -189,11 +197,15 @@ setMethod("cast",
 
 #' Match a column with given values.
 #'
-#' @rdname column
+#' @rdname match
+#' @name %in%
+#' @aliases %in%
 #' @return a matched values as a result of comparing with given values.
-#' @examples \dontrun{
-#'   filter(df, "age in (10, 30)")
-#'   where(df, df$age %in% c(10, 30))
+#' @export
+#' @examples
+#' \dontrun{
+#' filter(df, "age in (10, 30)")
+#' where(df, df$age %in% c(10, 30))
 #' }
 setMethod("%in%",
           signature(x = "Column"),
@@ -208,7 +220,10 @@ setMethod("%in%",
 #' If values in the specified column are null, returns the value. 
 #' Can be used in conjunction with `when` to specify a default value for expressions.
 #'
-#' @rdname column
+#' @rdname otherwise
+#' @name otherwise
+#' @family colum_func
+#' @export
 setMethod("otherwise",
           signature(x = "Column", value = "ANY"),
           function(x, value) {

From 949c79d67f2bbacd84316491e8cef43ce6f8c2d3 Mon Sep 17 00:00:00 2001
From: Yu ISHIKAWA <yuu.ishikawa@gmail.com>
Date: Tue, 25 Aug 2015 15:44:27 +0900
Subject: [PATCH 4/5] Add @name tags to cache, count, describe, printSchema and
 show

---
 R/pkg/R/DataFrame.R | 8 +++++++-
 R/pkg/R/column.R    | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index 749b9d864555d..7918268262ecb 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -62,6 +62,7 @@ dataFrame <- function(sdf, isCached = FALSE) {
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname printSchema
+#' @name printSchema
 #' @export
 #' @examples
 #'\dontrun{
@@ -186,6 +187,7 @@ setMethod("showDF",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname show
+#' @name show
 #' @export
 #' @examples
 #'\dontrun{
@@ -332,7 +334,8 @@ setMethod("insertInto",
 #'
 #' @param x A SparkSQL DataFrame
 #'
-#' @rdname cache-methods
+#' @rdname cache
+#' @name cache
 #' @export
 #' @examples
 #'\dontrun{
@@ -558,6 +561,7 @@ setMethod("sample_frac",
 #' @param x A SparkSQL DataFrame
 #'
 #' @rdname count
+#' @name count
 #' @aliases nrow
 #' @export
 #' @examples
@@ -1552,6 +1556,7 @@ setMethod("saveAsTable",
 #' @param ... Additional expressions
 #' @return A DataFrame
 #' @rdname describe
+#' @name describe
 #' @aliases summary
 #' @export
 #' @examples
@@ -1573,6 +1578,7 @@ setMethod("describe",
           })
 
 #' @rdname describe
+#' @name describe
 setMethod("describe",
           signature(x = "DataFrame"),
           function(x) {
diff --git a/R/pkg/R/column.R b/R/pkg/R/column.R
index d5dfd4525db0e..4805096f3f9c5 100644
--- a/R/pkg/R/column.R
+++ b/R/pkg/R/column.R
@@ -45,6 +45,7 @@ col <- function(x) {
 }
 
 #' @rdname show
+#' @name show
 setMethod("show", "Column",
           function(object) {
             cat("Column", callJMethod(object@jc, "toString"), "\n")

From 0a3f176ce2719a86e1430ffffed8c72b76e5fdb6 Mon Sep 17 00:00:00 2001
From: Yu ISHIKAWA <yuu.ishikawa@gmail.com>
Date: Tue, 25 Aug 2015 15:53:25 +0900
Subject: [PATCH 5/5] Move agg and groupBy to each Rd file

---
 R/pkg/R/DataFrame.R | 6 +++---
 R/pkg/R/generics.R  | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index 7918268262ecb..10f3c4ea59864 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -760,7 +760,7 @@ setMethod("first",
             take(x, 1)
           })
 
-# toRDD()
+# toRDD
 #
 # Converts a Spark DataFrame to an RDD while preserving column names.
 #
@@ -833,7 +833,7 @@ setMethod("group_by",
 #' Compute aggregates by specifying a list of columns
 #'
 #' @param x a DataFrame
-#' @rdname DataFrame
+#' @rdname agg
 #' @name agg
 #' @aliases summarize
 #' @export
@@ -843,7 +843,7 @@ setMethod("agg",
             agg(groupBy(x), ...)
           })
 
-#' @rdname DataFrame
+#' @rdname agg
 #' @name summarize
 setMethod("summarize",
           signature(x = "DataFrame"),
diff --git a/R/pkg/R/generics.R b/R/pkg/R/generics.R
index 610a8c31223cd..a829d46c1894c 100644
--- a/R/pkg/R/generics.R
+++ b/R/pkg/R/generics.R
@@ -441,7 +441,7 @@ setGeneric("filter", function(x, condition) { standardGeneric("filter") })
 #' @export
 setGeneric("group_by", function(x, ...) { standardGeneric("group_by") })
 
-#' @rdname DataFrame
+#' @rdname groupBy
 #' @export
 setGeneric("groupBy", function(x, ...) { standardGeneric("groupBy") })