"""HydroRoll-Team/echo
水系跨平台事件标准(cross-platform event standard): Event Communication and Harmonization across Online platforms.
:ref: https://github/com/HydroRoll-Team/echo
:ref: https://echo.hydroroll.team
"""

class WorkFlow(object):
    """workflow
    :ref: https://echo.hydroroll.team/Event/#1_workflow
    """
    
class CallBack(object):
    """callback
    :ref: https://echo.hydroroll.team/Event/#4_callback
    """