code: def test_sum_with_out(self, xp, sp):
      m = _make(xp, sp, self.dtype)
      if self.axis is None:
          shape = ()
      else:
          shape = list(m.shape)
          shape[self.axis] = 1
          shape = tuple(shape)
      out = xp.empty(shape, dtype=self.ret_dtype)
      if xp is numpy:
          # TODO(unno): numpy.matrix is used for scipy.sparse though
          # cupy.ndarray is used for cupyx.scipy.sparse.
          out = xp.asmatrix(out)
      return m.sum(axis=self.axis, dtype=self.ret_dtype, out=out)
  
imports: import pickle
  import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
  from cupy.cuda import driver
  from cupy.cuda import runtime
  from cupyx.scipy import sparse
label_desc: Use image node_id 3 for calling the TestDiaMatrixSum obj's underlying member method code with example usage: obj.test_sum_with_out(xp, sp) and returns: m