code: def conv2d(x_input, w_matrix):
      """conv2d returns a 2d convolution layer with full stride."""
      return tf.nn.conv2d(
          x_input, w_matrix, strides=[1, 1, 1, 1], padding="SAME"
      )
  
file_path: nni/examples/trials/mnist-tfv1/mnist.py
imports: import argparse
  import logging
  import math
  import tempfile
  import time
  import tensorflow
  from tensorflow.examples.tutorials.mnist import input_data
  import nni
label_desc: Use image node_id 1 for calling a global function with example usage: conv2d(x_input, w_matrix) and returns: tf