@krngrvr09 - you can add some docstrings in `astropy/table/groups.py`:

```
class ColumnGroups(BaseGroups):
    """
    Define the ``groups`` attribute in Table columns for grouping operations.
    """"
...
class TableGroups(BaseGroups):
    """
    Define the ``groups`` attribute in the Table class for grouping operations.
    """"
```
While you are at it, `ColumnGroups.aggregate` is missing a docstring (who wrote this code?!?).  This should suffice:
```
        """
        Aggregate each group in the Column into a single row by applying the reduction
        function ``func`` to group values in each column.

        Parameters
        ----------
        func : function
            Function that reduces an array of values to a single value

        Returns
        -------
        out : Column or Column subclass
            New column with the aggregated rows.
    """
```