<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def first_setup(self):
 """This is a guess of the meaning of this value."""

        if ATTR_FIRST_SETUP not in self.raw:
            return None
        return datetime.utcfromtimestamp(self.raw[ATTR_FIRST_SETUP])