Class that can be inherited to implement custom multiplayer API networking layers via GDExtension. This class is designed to be inherited from a GDExtension plugin to implement custom networking layers for the multiplayer API (such as WebRTC). All the methods below [b]must[/b] be implemented to have a working custom multiplayer implementation. See also [MultiplayerAPI]. Called when the available packet count is internally requested by the [MultiplayerAPI]. Called when the connection status is requested on the [MultiplayerPeer] (see [method MultiplayerPeer.get_connection_status]). Called when the maximum allowed packet size (in bytes) is requested by the [MultiplayerAPI]. Called when a packet needs to be received by the [MultiplayerAPI], with [param r_buffer_size] being the size of the binary [param r_buffer] in bytes. Called when the ID of the [MultiplayerPeer] who sent the most recent packet is requested (see [method MultiplayerPeer.get_packet_peer]). Called when a packet needs to be received by the [MultiplayerAPI], if [method _get_packet] isn't implemented. Use this when extending this class via GDScript. Called when the transfer channel to use is read on this [MultiplayerPeer] (see [member MultiplayerPeer.transfer_channel]). Called when the transfer mode to use is read on this [MultiplayerPeer] (see [member MultiplayerPeer.transfer_mode]). Called when the unique ID of this [MultiplayerPeer] is requested (see [method MultiplayerPeer.get_unique_id]). Called when the "refuse new connections" status is requested on this [MultiplayerPeer] (see [member MultiplayerPeer.refuse_new_connections]). Called when the "is server" status is requested on the [MultiplayerAPI]. See [method MultiplayerAPI.is_server]. Called when the [MultiplayerAPI] is polled. See [method MultiplayerAPI.poll]. Called when a packet needs to be sent by the [MultiplayerAPI], with [param p_buffer_size] being the size of the binary [param p_buffer] in bytes. Called when a packet needs to be sent by the [MultiplayerAPI], if [method _put_packet] isn't implemented. Use this when extending this class via GDScript. Called when the "refuse new connections" status is set on this [MultiplayerPeer] (see [member MultiplayerPeer.refuse_new_connections]). Called when the target peer to use is set for this [MultiplayerPeer] (see [method MultiplayerPeer.set_target_peer]). Called when the channel to use is set for this [MultiplayerPeer] (see [member MultiplayerPeer.transfer_channel]). Called when the transfer mode is set on this [MultiplayerPeer] (see [member MultiplayerPeer.transfer_mode]).