code: public static Http2Exception streamError(int id, Http2Error error, Throwable cause,
              String fmt, Object... args) {
          return CONNECTION_STREAM_ID == id ?
                  Http2Exception.connectionError(error, cause, fmt, args) :
                      new StreamException(id, error, String.format(fmt, args), cause);
      }
docs: Use if an error which can be isolated to a single stream has occurred.  If the {@code id} is not
  {@link Http2CodecUtil#CONNECTION_STREAM_ID} then a {@link Http2Exception.StreamException} will be returned.
  Otherwise the error is considered a connection error and a {@link Http2Exception} is returned.
  @param id The stream id for which the error is isolated to.
  @param error The type of error as defined by the HTTP/2 specification.
  @param cause The object which caused the error.
  @param fmt String with the content and format for the additional debug data.
  @param args Objects which fit into the format defined by {@code fmt}.
  @return If the {@code id} is not
  {@link Http2CodecUtil#CONNECTION_STREAM_ID} then a {@link Http2Exception.StreamException} will be returned.
  Otherwise the error is considered a connection error and a {@link Http2Exception} is returned.