Subclasses can override the add_element and remove_element to
update the list of children in the bin.
The handle_message method can be overridden to implement custom
message handling. handle_message takes ownership of the message, just like
#gst_element_post_message.
Subclasses can override the
add_elementandremove_elementto update the list of children in the bin. Thehandle_messagemethod can be overridden to implement custom message handling.handle_messagetakes ownership of the message, just like #gst_element_post_message.