remove out of date comment

src/cell.rs

@@ -212,8 +212,13 @@ impl Cell {
     #[inline]
     pub fn is_related_to(&self, other: &Self) -> bool {
         let common_res = std::cmp::min(self.res(), other.res());
-        // Unwrap is fine. We already checked to the min common resolution.
-        self.to_parent(common_res).unwrap() == other.to_parent(common_res).unwrap()
+        let promoted_self = self
+            .to_parent(common_res)
+            .expect("we already checked to the min common resolution");
+        let promoted_other = other
+            .to_parent(common_res)
+            .expect("we already checked to the min common resolution");
+        promoted_self == promoted_other
     }
 }
 

src/entry.rs

@@ -176,8 +176,7 @@ where
             }) => cell_value,
             Entry::Vacant(VacantEntry { target_cell, map }) => {
                 map.insert(target_cell, Default::default());
-                // We just inserted; unwrap is fine.
-                map.get_mut(target_cell).unwrap()
+                map.get_mut(target_cell).expect("we just inserted")
             }
         }
     }

src/node.rs

@@ -1,12 +1,5 @@
 use crate::{compaction::Compactor, digits::Digits, Cell};
 
-// TODO: storing indices in nodes is not necessary, since the index
-// can always be derived by the path through the tree to get to the
-// node. That said, storing the index doesn't impose much lookup
-// overhead.
-//
-// The benefit of storing indices is vastly simpler Cell+Value
-// iteration of a tree.
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(align(64))]