code: def test_diagonal(self):
      testing.assert_array_equal(
          self.m.diagonal(-2), cupy.array([0], self.dtype)
      )
      testing.assert_array_equal(
          self.m.diagonal(-1), cupy.array([3, 4], self.dtype)
      )
      testing.assert_array_equal(
          self.m.diagonal(), cupy.array([0, 1, 2], self.dtype)
      )
      testing.assert_array_equal(
          self.m.diagonal(1), cupy.array([0, 0, 0], self.dtype)
      )
      testing.assert_array_equal(
          self.m.diagonal(2), cupy.array([0, 0], self.dtype)
      )
      testing.assert_array_equal(
          self.m.diagonal(3), cupy.array([0], self.dtype)
      )
  
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 13 for calling the TestDiaMatrix obj's underlying member method code with example usage: obj.test_diagonal() without return types