code: def valid_path(*args):
      steps = []
      while args:
          key, index, *args = args
          steps.extend([Step(key=key), Step(index=index)])
      return Path(steps=steps)
  
imports: import itertools
  from absl.testing import parameterized
  import tensorflow
  from tfx.orchestration.portable.mlmd import event_lib
  from ml_metadata.proto import metadata_store_pb2
label_desc: Use image node_id 1 for calling a global function with example usage: valid_path() and returns: Path