nl_tokens: Check whether the trap result corresponds to the target s [[ Prototype ]]
pl_tokens: function ( ) { var trap = this . getTrap ( "getPrototypeOf" ) ; if ( trap === undefined ) { // default forwarding behavior return Reflect . getPrototypeOf ( this . target ) ; } var allegedProto = trap . call ( this . handler , this . target ) ; if ( ! Object_isExtensible ( this . target ) ) { var actualProto = Object_getPrototypeOf ( this . <mask> ) ; if ( ! sameValue ( allegedProto , actualProto ) ) { throw new TypeError ( "prototype value does not match: " + this . target ) ; } } return allegedProto ; }