docstr: A callable for `edge_convolution_template`.
code: def _pass_through(self, _, neighbor_features):
      """A callable for `edge_convolution_template`."""
      return neighbor_features
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import itertools
  from absl.testing import parameterized
  import numpy
  from six.moves import range
  import tensorflow
  import tensorflow_graphics.geometry.convolution.graph_convolution
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 2 for calling the EdgeConvolutionTemplateTests obj's underlying member method code with example usage: obj._pass_through(_, neighbor_features) and returns: neighbor_features