def _is_label_reference(self, key, axis=<NUM_LIT:0>):
if self.ndim > <NUM_LIT:2>:<EOL><INDENT>raise NotImplementedError(<EOL>"<STR_LIT>"<EOL>.format(type=type(self)))<EOL><DEDENT>axis = self._get_axis_number(axis)<EOL>other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis)<EOL>return (key is not None and<EOL>is_hashable(key) and<EOL>any(key in self.axes[ax] for ax in other_axes))<EOL>
Test whether a key is a label reference for a given axis.

To be considered a label reference, `key` must be a string that:
  - (axis=0): Matches a column label
  - (axis=1): Matches an index label

Parameters
----------
key: str
    Potential label name
axis: int, default 0
    Axis perpendicular to the axis that labels are associated with
    (0 means search for column labels, 1 means search for index labels)

Returns
-------
is_label: bool