code: def to_sample(self, inputs):
      src = tf.expand_dims(inputs, -1)
      pos = self.pos_sample_fn(inputs)
      negs = self.neg_sample_fn(inputs)
      assert (
          len(negs.get_shape().as_list()) == 2
          and len(pos.get_shape().as_list()) == 2
      )
      return src, pos, negs
  
file_path: euler/tf_euler/python/solution/base_unsupervise.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import tensorflow
  import tf_euler
  from tf_euler.python.solution.logits import PosNegLogits
  from tf_euler.python.solution.losses import xent_loss
label_desc: Use image node_id 4 for calling the UnsuperviseSolution obj's underlying member method code with example usage: obj.to_sample(inputs) and returns: src,  pos,  negs