code: def safe_sparse_dot(a, b, dense_output=False):
      
      if issparse(a) or issparse(b):
          ret = a * b
          if dense_output and hasattr(ret, "toarray"):
              ret = ret.toarray()
          return ret
      else:
          return np.dot(a, b)
docs: Dot product that handle the sparse matrix case correctly
      Uses BLAS GEMM as replacement for numpy.dot where possible
      to avoid unnecessary copies.
  
      Parameters
      ----------
      a : array or sparse matrix
      b : array or sparse matrix
      dense_output : boolean, default False
          When False, either ``a`` or ``b`` being sparse will yield sparse
          output. When True, output will always be an array.
      Returns
      -------
      dot_product : array or sparse matrix
          sparse if ``a`` or ``b`` is sparse and ``dense_output=False``.