class_docstr: A phase that simply relays train and eval datasets.
code: def work_units(self, previous_phase: Optional[Phase]):
      return []
  
file_path: adanet/adanet/experimental/phases/input_phase.py
imports: from typing import Optional
  from adanet.experimental.phases.phase import DatasetProvider
  from adanet.experimental.phases.phase import Phase
  import tensorflow.compat.v2
label_desc: Use image node_id 4 for calling the InputPhase obj's underlying member method code with example usage: obj.work_units(previous_phase) and returns: list