The function that will be called when the next element of the iterator
should be retrieved.
Implementors of a gstreamer.Iterator should implement this
function and pass it to the constructor of the custom iterator.
The function will be called with the iterator lock held.
The function that will be called when the next element of the iterator should be retrieved.
Implementors of a gstreamer.Iterator should implement this function and pass it to the constructor of the custom iterator. The function will be called with the iterator lock held.