lib/perform.js
function( kind, args ) {
  var bucket = this[ kind + 's' ];
  for ( var i = 0; i < bucket.length; i++ ) {
    callSet.call( this, bucket[i], args );
  }
}
function( kind, args ) {
  var bucket = this[ kind + 's' ];
  for ( var i = 0; i < bucket.length; i++ ) {
    callSet.call( this, bucket[i], args );
  }
}
call all the callback sets in a callback bucket