class_docstr: Graph for Gibbs sampling from Coconet.
code: def inputs(self):
      return self.placeholders
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import time
  from magenta.models.coconet import lib_graph
  from magenta.models.coconet import lib_hparams
  import numpy
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling the CoconetSampleGraph obj's underlying member method code with example usage: obj.inputs() and returns: self