in lib/src/copy/web_socket_impl.dart [367:376]
void _prepareForNextFrame() {
if (_state != CLOSED && _state != FAILURE) _state = START;
_fin = false;
_opcode = -1;
_len = -1;
_remainingLenBytes = -1;
_remainingMaskingKeyBytes = 4;
_remainingPayloadBytes = -1;
_unmaskingIndex = 0;
}