code: def encode_schedule(schedule):
      """Encodes a schedule tuple into a string.
  
      Args:
        schedule: A tuple containing (interpolation, steps, pmfs), where
          interpolation is a string specifying the interpolation strategy, steps
          is an int array_like of shape [N] specifying the global steps, and pmfs is
          an array_like of shape [N, M] where pmf[i] is the sampling distribution
          at global step steps[i]. N is the number of schedule requirements to
          interpolate and M is the size of the probability space.
  
      Returns:
        The string encoding of the schedule tuple.
      """
      interpolation, steps, pmfs = schedule
      return (
          interpolation
          + " "
          + " ".join(
              "@" + str(s) + " " + " ".join(map(str, p))
              for s, p in zip(steps, pmfs)
          )
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  import os
  import numpy
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_problems
  import tensorflow.compat.v1
label_desc: Use image node_id 9 for calling a global function with example usage: encode_schedule(schedule) and returns: unknown