Check that the specified array fits the previous rows size

def _check_row_size(self, array):
        """Check that the specified array fits the previous rows size
        """

        if not self._row_size:
            self._row_size = len(array)
        elif self._row_size != len(array):
            raise ArraySizeError, "array should contain %d elements" \
                % self._row_size