<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_atoms(self, inc_alt_states=False):
 """Returns all atoms in the `Monomer`. Parameters inc_alt_states : bool, optional If `True`, will return `Atoms` for alternate states. """

        if inc_alt_states:
            return itertools.chain(*[x[1].values() for x in sorted(list(self.states.items()))])
        return self.atoms.values()