code: function emitComments(comments, emitter, locs, eventName) {
  		if (comments.length > 0) {
  			comments.forEach(function(node) {
  				var index = locs.indexOf(node.loc);
  
  				if (index >= 0) {
  					locs.splice(index, 1);
  				} else {
  					locs.push(node.loc);
  					emitter.emit(node.type + eventName, node);
  				}
  			});
  		}
  	}
docs: ------------------------------------------------------------------------------ Helpers ------------------------------------------------------------------------------ 
  Check collection of comments to prevent double event for comment as
  leading and trailing, then emit event if passing
  @param {ASTNode[]} comments - Collection of comment nodes
  @param {EventEmitter} emitter - The event emitter which is the destination of events.
  @param {Object[]} locs - List of locations of previous comment nodes
  @param {string} eventName - Event name postfix
  @returns {void}