<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def relabel(self, qubits: Qubits) -> 'Channel': """Return a copy of this channel with new qubits"""

        chan = copy(self)
        chan.vec = chan.vec.relabel(qubits)
        return chan