code: def _mul_multimatrix(self, other):
      return np.hstack(
          [self._mul_vector(col).reshape(-1, 1) for col in other.T]
      )
  
imports: import numpy
  from ._matrix import spmatrix
  from ._base import issparse, _formats, _spbase, sparray
  from ._data import _data_matrix
  from ._sputils import isshape, upcast_char, getdtype, get_sum_dtype, validateaxis, check_shape
  from ._sparsetools import dia_matvec
label_desc: Use image node_id 9 for calling the _dia_base obj's underlying member method code with example usage: obj._mul_multimatrix(other) and returns: np