code: def compute_ref(
      self, alpha, A, x, beta, y, transpose_A, slice_tensors
  ):
      if transpose_A:
          A = A.T
      if slice_tensors:
          A = A[:: -self.slice_step]
          x = x[:: -self.slice_step]
          y = y[:: -self.slice_step]
      ref_val = alpha * np.dot(A, x)
      if beta != 0:
          ref_val += beta * y
      return ref_val
  
imports: from __future__ import absolute_import, print_function, division
  import sys
  import numpy
  from unittest import TestCase
  from nose.plugins.skip import SkipTest
  import theano
  import theano.tensor
  from theano.tensor.blas_c import CGer
  from theano.tensor.blas_scipy import ScipyGer
  from theano.tensor.blas import Ger
  from theano.tensor.blas_c import CGemv
  from theano.tensor.blas import Gemv
  from theano.tensor.blas_c import check_force_gemv_init
  from theano.tests import unittest_tools
  from theano.tests.unittest_tools import TestOptimizationMixin
  from theano.tensor.tests.test_blas import BaseGemv, TestBlasStrides
label_desc: Use image node_id 4 for calling the TestCGemvNoFlags obj's underlying member method code with example usage: obj.compute_ref(alpha, A, x, beta, y, transpose_A, slice_tensors) and returns: ref_val