class_docstr: A wallet stores the balance of a specific instrument on a specific exchange.
  
  Parameters
  ----------
  exchange : `Exchange`
      The exchange associated with this wallet.
  balance : `Quantity`
      The initial balance quantity for the wallet.
code: def __str__(self) -> str:
      return "<Wallet: balance={}, locked={}>".format(
          self.balance, self.locked_balance
      )
  
imports: from typing import Dict, Tuple
  from collections import namedtuple
  from decimal import Decimal
  import numpy
  from tensortrade.core import Identifiable
  from tensortrade.core.exceptions import InsufficientFunds, DoubleLockedQuantity, DoubleUnlockedQuantity, QuantityNotLocked
  from tensortrade.oms.instruments import Instrument, Quantity, ExchangePair
  from tensortrade.oms.orders import Order
  from tensortrade.oms.exchanges import Exchange
  from tensortrade.oms.wallets.ledger import Ledger
label_desc: Use image node_id 12 for calling the Wallet obj's underlying member method code with example usage: obj.__str__() and returns: str