<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_centralized_assembled_values(self, a):
 """Set assembled matrix values on processor 0."""

        if self.myid != 0:
            return
        assert a.size == self.id.nz
        self._refs.update(a=a)
        self.id.a = self.cast_array(a)