class_docstr: Mixin class for gemv tests 
class_docstr_tok: ["Mixin","class","for","gemv","tests"]
code: def test_x_stride_assert(self):
      # What is the use of this test?
      alpha, beta, a, x, y = self.get_data(x_stride=2)
      with pytest.raises(Exception, match="failed for 3rd argument"):
          y = self.blas_func(1, a, x, 1, y, trans=0, incx=3)
      with pytest.raises(Exception, match="failed for 3rd argument"):
          y = self.blas_func(1, a, x, 1, y, trans=1, incx=3)
  
imports: from numpy import float32, float64, complex64, complex128, arange, array, zeros, shape, transpose, newaxis, common_type, conjugate
  from scipy.linalg import _fblas
  from numpy.testing import assert_array_equal, assert_allclose, assert_array_almost_equal, assert_
  import pytest
label_desc: Use image node_id 8 for calling the BaseGemv obj's underlying member method code with example usage: obj.test_x_stride_assert() without return types