replaced candle_type: Optional[str] = '' with candle_type: str = ''

freqtrade/exchange/binance.py

@@ -200,15 +200,11 @@ class Binance(Exchange):
         except ccxt.BaseError as e:
             raise OperationalException(e) from e
 
-    async def _async_get_historic_ohlcv(
-        self,
-        pair: str,
-        timeframe: str,
-        since_ms: int,
-        is_new_pair: bool,
-        raise_: bool = False,
-        candle_type: Optional[str] = ""
-    ) -> Tuple[str, str, List]:
+    async def _async_get_historic_ohlcv(self, pair: str, timeframe: str,
+                                        since_ms: int, is_new_pair: bool = False,
+                                        raise_: bool = False,
+                                        candle_type: str = ''
+                                        ) -> Tuple[str, str, List]:
         """
         Overwrite to introduce "fast new pair" functionality by detecting the pair's listing date
         Does not work for other exchanges, which don't return the earliest data when called with "0"