class EngineEvent:
    def __init__(self, sVariableToModify, fLambda, tsArguments=None):
        self.sVariableToModify = sVariableToModify
        self.fLambda = fLambda
        if tsArguments is not None:
            self.tsArguments = tsArguments
        else:
            self.tsArguments = (sVariableToModify,)

class EngineEventProcessingError(Exception):
    pass