Call func with user_data for each of element's pads. func will be called
exactly once for each pad that exists at the time of this call, unless
one of the calls to func returns false in which case we will stop
iterating pads and return early. If new pads are added or pads are removed
while pads are being iterated, this will not be taken into account until
next time this function is used.
Call func with user_data for each of element's pads. func will be called exactly once for each pad that exists at the time of this call, unless one of the calls to func returns false in which case we will stop iterating pads and return early. If new pads are added or pads are removed while pads are being iterated, this will not be taken into account until next time this function is used.