code: def ParseFileVersion(file_version: str) -> float:
      """Convert the string file_version in event.proto into a float.
  
      Args:
        file_version: String file_version from event.proto
  
      Returns:
        Version number as a float.
      """
      tokens = file_version.split("brain.Event:")
      try:
          return float(tokens[-1])
      except ValueError:
          ## This should never happen according to the definition of file_version
          ## specified in event.proto.
          logger.warning(
              (
                  "Invalid event.proto file_version. Defaulting to use of "
                  "out-of-order event.step logic for purging expired events."
              )
          )
          return -1
  
imports: from typing import Optional
  from tensorboard.compat.proto import event_pb2
  from tensorboard.util import tb_logging
label_desc: Use image node_id 1 for calling a global function with example usage: ParseFileVersion(file_version) and returns: float, unknown