'Convert custom URI scheme to real playable URI.
*MAY be reimplemented by subclass.*
This is very likely the *only* thing you need to override as a backend
author. Typically this is where you convert any Mopidy specific URI
to a real URI and then return it. If you can\'t convert the URI just
return :class:`None`.
:param uri: the URI to translate
:type uri: string
:rtype: string or :class:`None` if the URI could not be translated'

def translate_uri(self, uri):

    return uri
