class_docstr: Reward calculation component that takes a single argument: state of simulator. Returns a real number: reward.
  
  Subclass should implement ``reward(simulator_state)`` to implement their own reward calculation recipe.
code: def log(self, name: str, value: Any) -> None:
      assert self.env is not None
      self.env.logger.add_scalar(name, value)
  
file_path: qlib/qlib/rl/reward.py
imports: from __future__ import annotations
  from typing import TYPE_CHECKING, Any, Dict, Generic, Optional, Tuple, TypeVar
  from qlib.typehint import final
label_desc: Use image node_id 3 for calling the Reward obj's underlying member method code with example usage: obj.log(name, value) without return types