restore bpd to datetimelike

Author: tswast

third_party/bigframes_vendored/pandas/core/arrays/datetimelike.py

@@ -50,6 +50,8 @@ def normalize(self):
 
         **Examples:**
 
+            >>> import bigframes.pandas as bpd
+
             >>> s = bpd.Series(pd.date_range(
             ...     start='2014-08-01 10:00',
             ...     freq='h',