docstr: Catch-all for small edge cases
docstr_tok: ["Catch-all","for","small","edge","cases"]
code: def test_edge_cases(self):
      """Catch-all for small edge cases"""
  
      A, B, C, D = self.data()
  
      expected = cupy.asarray([[7]], dtype=self.dtype)
      testing.assert_array_equal(
          _construct.bmat([[None, D], [C, None]]).todense(), expected
      )
  
imports: import functools
  import re
  from unittest import mock
  import numpy
  import pytest
  import cupy
  from cupy import testing
  from cupy.cuda import runtime
  from cupyx.scipy import sparse
  from cupyx.scipy.sparse import _construct
label_desc: Use image node_id 4 for calling the TestBmat obj's underlying member method code with example usage: obj.test_edge_cases() without return types