code: def sparsity_pattern(self, reordered = True, symmetric = True):
          
          return cspmatrix(self, 1.0).spmatrix(reordered = reordered, symmetric = symmetric)
docs: Returns a sparse matrix with the filled pattern. By default,
          the routine uses the reordered pattern, and the inverse
          permutation is applied if `reordered` is `False`.
          
          :param reordered:  boolean (default: `True`)
          :param symmetric:  boolean (default: `True`)