def LOG(number, base):
return {'<STR_LIT>': [number, base]}<EOL>
Calculates the log of a number in the specified base and returns the result as a double.
See https://docs.mongodb.com/manual/reference/operator/aggregation/log/
for more details
:param number: The number or field of number
:param base: The base of log operation
:return: Aggregation operator