code: public String[] values(String name) {
          final HttpHeader header = getHeader(name);
          return header == null ? null : header.values();
      }
docs: Get the header values for the provided header name. Null will be returned if
  the header name isn't found.
  
  @param name the name of the header to look for
  @return the values of the header, or null if the header isn't found