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 warnings import warn
  import numpy
  import pytest
  import pytensor
  import pytensor.tensor
  from pytensor.misc.safe_asarray import _asarray
  from pytensor.tensor.basic import AllocEmpty
  from pytensor.tensor.blas import Ger
  from pytensor.tensor.blas_c import CGemv, CGer, check_force_gemv_init
  from pytensor.tensor.blas_scipy import ScipyGer
  from pytensor.tensor.type import dmatrix, dvector, matrix, scalar, tensor, vector
  from tests import unittest_tools
  from tests.tensor.test_blas import BaseGemv, TestBlasStrides
  from tests.unittest_tools import OptimizationTestMixin
label_desc: Use image node_id 3 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