Validate an array for post-fit tasks.

        Parameters
        ----------
        X : Union[Array, DataFrame]

        Returns
        -------
        same type as 'X'

        Notes
        -----
        The following checks are applied.

        - Ensure that the array is blocked only along the samples.

def _check_array(self, X):
        """Validate an array for post-fit tasks.

        Parameters
        ----------
        X : Union[Array, DataFrame]

        Returns
        -------
        same type as 'X'

        Notes
        -----
        The following checks are applied.

        - Ensure that the array is blocked only along the samples.
        """
        if isinstance(X, da.Array):
            if X.ndim == 2 and X.numblocks[1] > 1:
                logger.debug("auto-rechunking 'X'")
                if not np.isnan(X.chunks[0]).any():
                    X = X.rechunk({0: "auto", 1: -1})
                else:
                    X = X.rechunk({1: -1})
        return X