text: 
  var express = require('../')
    , should = require('should');
  
  function response() {
    var res = Object.create(express.response);
    res._headers = {};
    return res;
  }
  
  describe.skip('res.vary()', function(){
    describe('with no arguments', function(){
      it('should not set Vary', function(){
        var res = response();
        res.vary();
        should.not.exist(res.get('Vary'));
      })
    })
  
    describe('with an empty array', function(){
      it('should not set Vary', function(){
        var res = response();
        res.vary([]);
        should.not.exist(res.get('Vary'));
      })
    })
  
    describe('with an array', function(){
      it('should set the values', function(){
        var res = response();
        res.vary(['Accept', 'Accept-Language', 'Accept-Encoding']);
        res.get('Vary').should.equal('Accept, Accept-Language, Accept-Encoding');
      })
    })
  
    describe('with a string', function(){
      it('should set the value', function(){
        var res = response();
        res.vary('Accept');
        res.get('Vary').should.equal('Accept');
      })
    })
  
    describe('when the value is present', function(){
      it('should not add it again', function(){
        var res = response();
        res.vary('Accept');
        res.vary('Accept-Encoding');
        res.vary('Accept-Encoding');
        res.vary('Accept-Encoding');
        res.vary('Accept');
        res.get('Vary').should.equal('Accept, Accept-Encoding');
      })
    })
  })
  