code: def diff(x, prepend=None):
      """Like jnp.diff."""
      if prepend is not None:
          x = tf.concat(
              [
                  tf.convert_to_tensor(prepend, dtype=x.dtype)[
                      tf.newaxis
                  ],
                  x,
              ],
              0,
          )
      return x[1:] - x[:-1]
  
imports: import functools
  import numpy
  import six
  import tensorflow.compat.v2
  from tensorflow.python.util import nest
label_desc: Use image node_id 22 for calling a global function with example usage: diff(x, prepend) and returns: unknown