code: def _directly_calls(graph):
      """Set of Functions directly called by the given graph."""
      # TODO(axch): Deduplicate this and _directly_writes into a generic CFG
      # traversal?
      answer = set()
      for i in range(graph.exit_index()):
          block = graph.block(i)
          for op in block.instructions:
              if isinstance(op, inst.FunctionCallOp):
                  answer.add(op.function)
      return answer
  
file_path: probability/tensorflow_probability/python/experimental/auto_batching/allocation_strategy.py
imports: from absl import logging
  import six
  from tensorflow_probability.python.experimental.auto_batching import instructions
  from tensorflow_probability.python.experimental.auto_batching import liveness
label_desc: Use image node_id 8 for calling a global function with example usage: _directly_calls(graph) and returns: answer