code: def test_overflow(self, xp, dtype):
      value = numpy.iinfo(dtype).max
      a = xp.array([value - 10]).astype(dtype)
      b = xp.array([value - 10]).astype(dtype)
      return xp.matmul(a, b)
  
imports: import operator
  import unittest
  import numpy
  import pytest
  import cupy
  from cupy._core import _routines_linalg
  from cupy import testing
label_desc: Use image node_id 1 for calling the TestMatmulOverflow obj's underlying member method code with example usage: obj.test_overflow(xp, dtype) and returns: xp