Format existing code with black

IPython/utils/tz.py

@@ -24,6 +24,7 b' from datetime import tzinfo, timedelta, datetime'
 # constant for zero offset
 ZERO = timedelta(0)
 
+
 class tzUTC(tzinfo):
     """tzinfo object for UTC (zero offset)"""
 
@@ -39,10 +40,13 b' UTC = tzUTC() # type: ignore[abstract]'
 
 def utc_aware(unaware):
     """decorator for adding UTC tzinfo to datetime's utcfoo methods"""
+
     def utc_method(*args, **kwargs):
         dt = unaware(*args, **kwargs)
         return dt.replace(tzinfo=UTC)
+
     return utc_method
 
+
 utcfromtimestamp = utc_aware(datetime.utcfromtimestamp)
 utcnow = utc_aware(datetime.utcnow)