docstr: A callable for `edge_convolution_template`.
code: def _zeros(self, vertex_features, _, out_dimensions=None):
      """A callable for `edge_convolution_template`."""
      if out_dimensions is None:
          return tf.zeros_like(vertex_features)
      else:
          return tf.zeros(
              shape=(
                  vertex_features.shape.as_list()[0],
                  out_dimensions,
              ),
              dtype=vertex_features.dtype,
          )
  
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 1 for calling the EdgeConvolutionTemplateTests obj's underlying member method code with example usage: obj._zeros(vertex_features, _, out_dimensions) and returns: tf, tf