text: function Caseless(dict) {
      this.dict = dict || {}
  }
  Caseless.prototype.set = function (name, value, clobber) {
      if (typeof name === 'object') {
          for (var i in name) {
              this.set(i, name[i], value)
          }
      } else {
          if (typeof clobber === 'undefined') clobber = true
          var has = this.has(name)
  
          if (!clobber && has) this.dict[has] = this.dict[has] + ',' + value
          else this.dict[has || name] = value
          return has
      }
  }
  Caseless.prototype.has = function (name) {
      var keys = Object.keys(this.dict)
          , name = name.toLowerCase()
      ;
      for (var i = 0; i < keys.length; i++) {
          if (keys[i].toLowerCase() === name) return keys[i]
      }
      return false
  }
  Caseless.prototype.get = function (name) {
      name = name.toLowerCase()
      var result, _key
      var headers = this.dict
      Object.keys(headers).forEach(function (key) {
          _key = key.toLowerCase()
          if (name === _key) result = headers[key]
      })
      return result
  }
  Caseless.prototype.swap = function (name) {
      var has = this.has(name)
      if (!has) throw new Error('There is no header than matches "' + name + '"')
      this.dict[name] = this.dict[has]
      delete this.dict[has]
  }
  Caseless.prototype.del = function (name) {
      var has = this.has(name)
      return delete this.dict[has || name]
  }
  
  module.exports = function (dict) {
      return new Caseless(dict)
  }
  module.exports.httpify = function (resp, headers) {
      var c = new Caseless(headers)
      resp.setHeader = function (key, value, clobber) {
          if (typeof value === 'undefined') return
          return c.set(key, value, clobber)
      }
      resp.hasHeader = function (key) {
          return c.has(key)
      }
      resp.getHeader = function (key) {
          return c.get(key)
      }
      resp.removeHeader = function (key) {
          return c.del(key)
      }
      resp.headers = c.dict
      return c
  }
  