def MILLISECOND(expression):
return {'<STR_LIT>': expression}<EOL>
Returns the millisecond portion of a date as an integer between 0 and 999.
See https://docs.mongodb.com/manual/reference/operator/aggregation/millisecond/
for more details
:param expression: expression or variable of a Date, a Timestamp, or an ObjectID
:return: Aggregation operator