@property<EOL><INDENT>def _ndarray_values(self) -> np.ndarray:<DEDENT>
if is_extension_array_dtype(self):<EOL><INDENT>return self.array._ndarray_values<EOL><DEDENT>return self.values<EOL>
The data as an ndarray, possibly losing information.

The expectation is that this is cheap to compute, and is primarily
used for interacting with our indexers.

- categorical -> codes