code: def net_worths():
      return pd.Series(
          [100, 400, 350, 450, 200, 400, 330, 560], name="net_worth"
      )
  
file_path: tensortrade/tests/tensortrade/unit/env/default/test_rewards.py
imports: import pytest
  import numpy
  import pandas
  from collections import OrderedDict
  import tensortrade.env.default.rewards
  from tensortrade.core import TradingContext
  from tensortrade.oms.wallets import Portfolio
  from tensortrade.oms.instruments import USD
label_desc: Use image node_id 1 for calling a global function with example usage: net_worths() and returns: pd