code: function (header) {
          if (!_.isString(header)) { return { key: E, value: E }; }
  
          var index = header.indexOf(HEADER_KV_SEPARATOR),
              key,
              value;
  
          (index < 0) && (index = header.length);
  
          key = header.substr(0, index);
          value = header.substr(index + 1);
  
          return {
              key: _.trim(key),
              value: _.trim(value)
          };
      }
docs: Parses a single Header.
  
  @param {String} header
  @returns {{key: string, value: string}}