code: def _mul_vector(self, other):
      x = other
  
      y = np.zeros(
          self.shape[0],
          dtype=upcast_char(self.dtype.char, x.dtype.char),
      )
  
      L = self.data.shape[1]
  
      M, N = self.shape
  
      dia_matvec(
          M,
          N,
          len(self.offsets),
          L,
          self.offsets,
          self.data,
          x.ravel(),
          y.ravel(),
      )
  
      return y
  
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 8 for calling the _dia_base obj's underlying member method code with example usage: obj._mul_vector(other) and returns: y