Remove timezone from what will become asString

Author: katcharov

driver-core/src/main/com/mongodb/client/model/expressions/DateExpression.java

@@ -31,7 +31,7 @@ public interface DateExpression extends Expression {
     IntegerExpression week(StringExpression timezone);
     IntegerExpression millisecond(StringExpression timezone);
 
-    StringExpression dateToString(StringExpression timezone);
+    StringExpression dateToString();
     StringExpression dateToString(StringExpression timezone, StringExpression format);
 
 }

driver-core/src/main/com/mongodb/client/model/expressions/MqlExpression.java

@@ -391,10 +391,9 @@ public IntegerExpression millisecond(final StringExpression timezone) {
     }
 
     @Override
-    public StringExpression dateToString(final StringExpression timezone) {
+    public StringExpression dateToString() {
         return newMqlExpression((cr) -> astDoc("$dateToString", new BsonDocument()
-                .append("date", this.toBsonValue(cr))
-                .append("timezone", extractBsonValue(cr, timezone))));
+                .append("date", this.toBsonValue(cr))));
     }
 
     @Override

driver-core/src/test/functional/com/mongodb/client/model/expressions/DateExpressionsFunctionalTest.java

@@ -136,7 +136,8 @@ public void dateToStringTest() {
         // https://www.mongodb.com/docs/manual/reference/operator/aggregation/dateToString/
         assertExpression(
                 utcDateTime.toInstant().toString(),
-                utcDateEx.dateToString(utc));
+                utcDateEx.dateToString(),
+                "{'$dateToString': {'date': {'$date': '2007-12-03T10:15:30.005Z'}}}");
         // with parameters
         assertExpression(
                 utcDateTime.withZoneSameInstant(ZoneId.of("America/New_York")).format(ISO_LOCAL_DATE_TIME),