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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def __event_exist(self, event_type):
 """Return the event position, if it exists. An event exist if: * end is < 0 * event_type is matching Return -1 if the item is not found. """

        for i in range(self.len()):
            if self.events_list[i][1] < 0 and self.events_list[i][3] == event_type:
                return i
        return -1