code: def to_sample(self, inputs):
      inputs = self.parse_input_fn(inputs)
      neg = []
      pos = []
      if len(inputs) == 2 and inputs[1] is not None:
          neg.append(inputs[1])
      if len(inputs) == 3:
          pos.append(inputs[2])
  
      if self.pos_sample_fn is not None:
          src, pos_from_fn = self.pos_sample_fn(inputs[0])
          pos.append(pos_from_fn)
      else:
          src = inputs[0]
      if self.neg_sample_fn is not None:
          neg.append(self.neg_sample_fn(inputs[0]))
      pos = tf.concat(pos, axis=-1)
      neg = tf.concat(neg, axis=-1)
      return src, pos, neg
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import tensorflow
  import tf_euler
  import six
  from tf_euler.python.solution.logits import CosineLogits, PosNegLogits
  from tf_euler.python.solution.losses import sigmoid_loss, xent_loss
  from tf_euler.python.solution.base_unsupervise import UnsuperviseSolution
label_desc: Use image node_id 4 for calling the UnsuperviseSampleSolution obj's underlying member method code with example usage: obj.to_sample(inputs) and returns: src,  pos,  neg