docs: def set_centralized_sparse(self, A):
          """Set assembled matrix on processor 0.
  
          Parameters
          ----------
          A : `scipy.sparse.coo_matrix`
              Sparse matrices of other formats will be converted to
              COOrdinate form.
          """
          if self.myid != 0:
              return
  
          A = A.tocoo()
          n = A.shape[0]
          assert A.shape == (n, n), "Expected a square matrix."
          self.set_shape(n)
          self.set_centralized_assembled(A.row+1, A.col+1, A.data)