A css icon class of this handler.
A unique id of this handler.
A human-readable name of this handler.
Test whether this handler can open the given URI for given options. Return a nonzero number if this handler can open; otherwise it cannot. Never reject.
A returned value indicating a priority of this handler.
Open a widget for the given URI and options.
Resolve to an opened widget or undefined, e.g. if a page is opened.
Never reject if canHandle return a positive number; otherwise should reject.
OpenHandlershould be implemented to provide a new opener.