def insert(self, key, obj, future_expiration_minutes=<NUM_LIT:15>):
expiration_time = self._calculate_expiration(future_expiration_minutes)<EOL>self._CACHE[key] = (expiration_time, obj)<EOL>return True<EOL>
Insert item into cache.

:param key: key to look up in cache.
:type key: ``object``

:param obj: item to store in cache.
:type obj: varies

:param future_expiration_minutes: number of minutes item is valid
:type param: ``int``

:returns: True
:rtype: ``bool``