code: def flatten(_input):
      input_shape = _input.shape.as_list()
      if len(input_shape) != 2:
          return tf.reshape(_input, [-1, np.prod(input_shape[1:])])
      else:
          return _input
  
imports: import os
  import shutil
  import tensorflow
  import numpy
  import time
  from datetime import timedelta
  import json
  import pickle
label_desc: Use image node_id 26 for calling the BasicModel obj's underlying member method code with example usage: obj.flatten(_input) and returns: tf, _input