Call function from custom component

Hey. How would I call this function https://github.com/home-assistant/home-assistant/blob/004af97699f892093c1c25f1bba0a6359773f61b/homeassistant/components/calendar/init.py#L191-L193

that is the same as calling:

http://homeassistant:8123/api/calendars/calendar.***?start=***&end=***

from my component?