def _maybe_coerce_values(self, values):
if values.dtype != _NS_DTYPE:<EOL><INDENT>values = conversion.ensure_datetime64ns(values)<EOL><DEDENT>if isinstance(values, DatetimeArray):<EOL><INDENT>values = values._data<EOL><DEDENT>assert isinstance(values, np.ndarray), type(values)<EOL>return values<EOL>
Input validation for values passed to __init__. Ensure that
        we have datetime64ns, coercing if necessary.

        Parameters
        ----------
        values : array-like
            Must be convertible to datetime64

        Returns
        -------
        values : ndarray[datetime64ns]

        Overridden by DatetimeTZBlock.