/**
 * Handles listening for events and responding to them by creating the text
 * highlights.
 */ export namespace TextHighlighterListener { export function start ( ) { function handleMessage ( event ) { switch ( event . data . type ) { } } window . addEventListener ( 'message' , handleMessage ) ; return ( ) => { if ( window && typeof window . removeEventListener === 'function' ) { window . removeEventListener ( 'message' , handleMessage ) ; } } ; } }