code: def _variable_on_cpu(name, shape, initializer):
    
    with tf.device('/cpu:0'):
      dtype = tf.float16 if FLAGS.use_fp16 else tf.float32
      var = tf.get_variable(name, shape, initializer=initializer, dtype=dtype)
    return var
docs: Helper to create a Variable stored on CPU memory.
  
    Args:
      name: name of the variable
      shape: list of ints
      initializer: initializer for Variable
  
    Returns:
      Variable Tensor