stylelint-bundle-worker.js
function () {
    var me = this;
    var obj = { };

    var keys = Object.keys( me._visited );

    // no keys visited for either get or set value
    if ( keys.length === 0 ) {
      return;
    }

    keys.forEach( function ( key ) {
      obj[ key ] = me._persisted[ key ];
    } );

    me._visited = { };
    me._persisted = obj;
  }
function () {
    var me = this;
    var obj = { };

    var keys = Object.keys( me._visited );

    // no keys visited for either get or set value
    if ( keys.length === 0 ) {
      return;
    }

    keys.forEach( function ( key ) {
      obj[ key ] = me._persisted[ key ];
    } );

    me._visited = { };
    me._persisted = obj;
  }
Remove keys that were not accessed/set since the
last time the `prune` method was called.
@method _prune
@private