function clear() {
        for (var that = _validateCollection(this, NAME), data = that._i, entry = that._f; entry; entry = entry.n) {
          entry.r = true;
          if (entry.p) entry.p = entry.p.n = undefined;
          delete data[entry.i];
        }
        that._f = that._l = undefined;
        that[SIZE] = 0;
      }
function clear() {
        for (var that = _validateCollection(this, NAME), data = that._i, entry = that._f; entry; entry = entry.n) {
          entry.r = true;
          if (entry.p) entry.p = entry.p.n = undefined;
          delete data[entry.i];
        }
        that._f = that._l = undefined;
        that[SIZE] = 0;
      }
function clear ( ) { for ( var that = _validateCollection ( this , NAME ) , data = that . _i , entry = that . _f ; entry ; entry = entry . n ) { entry . r = true ; if ( entry . p ) entry . p = entry . p . n = undefined ; delete data [ entry . i ] ; } that . _f = that . _l = undefined ; that [ SIZE ] = 0 ; }
23.1.3.1 Map.prototype.clear() 23.2.3.2 Set.prototype.clear()
23 . 1 . 3 . 1 Map . prototype . clear () 23 . 2 . 3 . 2 Set . prototype . clear ()