# Functions
NewListenerWrapper creates a new listenerWrapper with params.
# Structs
ListenerWrapperParams wraps parameters required to create a listenerWrapper.
# Interfaces
XDSClient wraps the methods on the XDSClient which are required by the listenerWrapper.
# Type aliases
DrainCallback is the callback that an xDS-enabled server registers to get notified about updates to the Listener configuration.
ServingModeCallback is the callback that users can register to get notified about the server's serving mode changes.