class Constants:
    ENTER_RAW_MODE = b'\x01'  # CTRL-A
    ENTER_REPL_MODE = b'\x02' # CTRL-B
    INTERRUPT = b'\x03'       # CTRL-C
    CTRL_D = b'\x04'          # CTRL-D
    MARKER_BEGIN = b'>>>>>>>>>>'
    MARKER_END = b'<<<<<<<<<<'