Cache result of search() in case it's called twice.

[nm17]

Since the function is called on __init__ and it's result is stored in self.videos, you should return the self.videos on search() or add an optional parameter like dont_cache=False to the function.

[joetats]

Ah - I'll add some flags to the to_dict() and to_json() methods to clear the property on default, and save it otherwise