code: public static <T extends Header> T getHeader(final Header[] hdrs, short id) {
          if(hdrs == null)
              return null;
          for(Header hdr: hdrs) {
              if(hdr == null)
                  return null;
              if(hdr.getProtId() == id)
                  return (T)hdr;
          }
          return null;
      }
docs: Returns the header associated with an ID
  @param id The ID
  @return