nl_tokens: Create a getter for the given header name .
pl_tokens: function createHeaderGetter ( str ) { var name = str . toLowerCase ( ) return function ( req , res ) { // set appropriate Vary header vary ( res , str ) // get header var header = req . <mask> [ name ] if ( ! header ) { return undefined } // multiple headers get joined with comma by node.js core var index = header . indexOf ( ',' ) // return first value return index !== - 1 ? header . substr ( 0 , index ) . trim ( ) : header . trim ( ) } }