class_docstr: Partial triple source adding graph nodes for constructing and keeping track
  of triples and their use. Subclasses must implement `_build_queues`.
class_docstr_tok: ["Partial","triple","source","adding","graph","nodes","for","constructing","and","keeping","track","of","triples","and","their","use",".","Subclasses","must","implement","`","_build_queues","`","."]
code: def gather_mask(self, a, indices, axis):
      with tf.name_scope("mask-transformation"):
          with tf.device(self.producer.device_name):
              a_g = a.gather(indices, axis=axis)
  
      return a_g
  
imports: import abc
  import logging
  import random
  import tensorflow
  from ...config import get_config
label_desc: Use image node_id 9 for calling the BaseTripleSource obj's underlying member method code with example usage: obj.gather_mask(a, indices, axis) and returns: a_g