code: def check_forward_no_cast(self, x_data):
      y = functions.cast(x_data, self.dtype)
      assert isinstance(y, chainer.Variable)
      assert y.data is x_data
  
imports: import unittest
  import numpy
  import chainer
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  import chainerx
label_desc: Use image node_id 2 for calling the TestNoCast obj's underlying member method code with example usage: obj.check_forward_no_cast(x_data) without return types