nl_tokens: Returns a fresh property descriptor whose standard attributes are guaranteed to be data properties of the right type . Additionally any non - standard enumerable properties of attributes are copied over to the fresh descriptor .
pl_tokens: function normalizePropertyDescriptor ( attributes ) { var desc = toPropertyDescriptor ( attributes ) ; // Note: no need to call FromGenericPropertyDescriptor(desc), as we represent // "internal" property descriptors as proper Objects from the start for ( var name in attributes ) { if ( ! isStandardAttribute ( name ) ) { Object . defineProperty ( desc , name , { <mask> : attributes [ name ] , writable : true , enumerable : true , configurable : true } ) ; } } return desc ; }