code: def check_raises(
      self,
      a_shape,
      y_shape=None,
      rowvar=True,
      bias=False,
      ddof=None,
      dtype=None,
      fweights=None,
      aweights=None,
  ):
      for xp in (numpy, cupy):
          a, y = self.generate_input(a_shape, y_shape, xp, dtype)
          with pytest.raises(ValueError):
              xp.cov(
                  a,
                  y,
                  rowvar,
                  bias,
                  ddof,
                  fweights,
                  aweights,
                  dtype=dtype,
              )
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 4 for calling the TestCov obj's underlying member method code with example usage: obj.check_raises(a_shape, y_shape, rowvar, bias, ddof, dtype, fweights, aweights) without return types