class_docstr: Unit with inner state.
  
  Usually need to be fit before transforming. All information gathered in the
  fit phrase will be stored into its `context`.
docstr: Get current context. Same as `unit.state`.
code: def context(self):
      """Get current context. Same as `unit.state`."""
      return self._context
  
file_path: MatchZoo/matchzoo/preprocessors/units/stateful_unit.py
imports: import abc
  import typing
  from .unit import Unit
label_desc: Use image node_id 3 for calling the StatefulUnit obj's underlying member method code with example usage: obj.context() and returns: self