class_docstr: Visitor to determine if a node is ready to run.
class_docstr_tok: ["Visitor","to","determine","if","a","node","is","ready","to","run","."]
code: def validate_operation_def(self, operation_def):
      assert (
          operation_def.label not in self._visited_operation_def_labels
      )
      self._visited_operation_def_labels.add(operation_def.label)
  
imports: import collections
  import dataclasses
  from typing import Sequence
  from tensorflow_transform import analyzer_nodes
  from tensorflow_transform import nodes
  from tensorflow_transform.beam import beam_nodes
label_desc: Use image node_id 2 for calling the _ValidationVisitor obj's underlying member method code with example usage: obj.validate_operation_def(operation_def) without return types