code: def call(self, x):
      x = PF.convolution(
          x,
          outmaps=self.outmaps,
          kernel=self.kernel,
          pad=self.pad,
          stride=self.stride,
      )
      if self.is_last is False:
          x = F.relu(x)
      return x
  
imports: import nnabla
  import nnabla.parametric_functions
  import nnabla.functions
  import numpy
  import pytest
  from helper import create_temp_with_dir
  from nnabla.testing import assert_allclose
label_desc: Use image node_id 2 for calling the ConvLayer obj's underlying member method code with example usage: obj.call(x) and returns: x