nl_tokens: Multi - Key LRU cache .
pl_tokens: function MultiKeyCache ( options ) { options = options || { } ; var <mask> = this ; var dispose = options . dispose ; options . dispose = function ( key , value ) { self . _dispose ( key ) ; if ( dispose ) { dispose ( key , value ) ; } } ; this . cache = new LRU ( options ) ; this . _keyMap = { } ; }