ErrBadMetadata bad metadata.

ErrBadRequest bad request.

ErrCanceled canceled.

ErrConnectionChClosed connection channel been closed.

ErrFailedToAllocatePort failed to allocate port.

ErrFailedToListen cannot listen on an address, or bad port.

ErrFailedToRegisterAddr failed to register addr.

ErrMsgChanClosed message type channel been closed.

ErrNotSupport not support this function.

ErrTokenNotValid token not valid.