query

Execute a specialized query (specific for each provider) on a media repository.

It is different from search semantically, because the query implies a carefully crafted string, rather than a simple string to search.

This method is asynchronous.

Parameters:

this	a source
callback	the user defined callback
keys	the List of KeyID<!-- -- >s to request
options	options wanted for that operation
query	the query to process
user_data	the user data to pass in the callback

Returns:

the operation identifier