Asynchronously performs a forward geocoding query using the this.
Use forward_search to do the same thing synchronously.
The params
hash table is in the format used by Telepathy, and documented in the [Telepathy
specification](http://telepathy.freedesktop.org/spec/Connection_Interface_Location.html#Mapping:Location).
See also: [XEP-0080 specification](http://xmpp.org/extensions/xep-0080.html).
When the operation is finished, callback
will be called. You can then call
forward_search_async.end to get the result of the operation.
this |
a Backend. |
cancellable |
optional Cancellable, |
callback |
a TaskReadyCallback to call when the request is satisfied |
params |
a GenericSet with string keys, and Value values. |
user_data |
the data to pass to the |