Add type-hint to exchange_has dict

freqtrade/exchange/common.py

@@ -2,7 +2,7 @@ import asyncio
 import logging
 import time
 from functools import wraps
-from typing import Any, Callable, Optional, TypeVar, cast, overload
+from typing import Any, Callable, Dict, List, Optional, TypeVar, cast, overload
 
 from freqtrade.constants import ExchangeConfig
 from freqtrade.exceptions import DDosProtection, RetryableOrderError, TemporaryError
@@ -61,7 +61,7 @@ SUPPORTED_EXCHANGES = [
 ]
 
 # either the main, or replacement methods (array) is required
-EXCHANGE_HAS_REQUIRED = {
+EXCHANGE_HAS_REQUIRED: Dict[str, List[str]] = {
     # Required / private
     'fetchOrder': ['fetchOpenOrder', 'fetchClosedOrder'],
     'cancelOrder': [],