nl_tokens: Given a defaults object and a source object copy the value from the source if it contains the same key otherwise return the default . Skip keys that only exist in the source object .
pl_tokens: function merge_or_apply ( defaults , source ) { var defaultKeys = keys ( defaults ) ; var sourceKeys = keys ( source ) ; return reduce ( defaultKeys , function ( result , key ) { if ( sourceKeys . indexOf ( key ) > - 1 ) { result [ key ] = source [ <mask> ] ; return result ; } else { result [ key ] = defaults [ key ] ; return result ; } } , { } ) ; }