<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def Update(self, other, callback):
 """Adds existing triggers to this set, optionally rebuilding the registry. Used to aggregate trigger methods from Probes to Methods to Checks. Args: other: Another Triggers object. callback: Registers all the updated triggers to the specified function. """

    self.conditions.update(other.conditions)
    self._Register(other.conditions, callback)