input: [0] sources [1] optional [3] a list of the weather sources that contributed to build this WeatherPoint [2] 
output: list of strings
options: T a g
options: t i m e s t a m p
options: W e a t h e r
options: G e o J S O N
options: L o c a t i o n
options: s t r i n g
options: n u m b e r
options: l i s t o f s t r i n g s