code: func (cs callSet) Remove(call *Call) {
  	key := callSetKey{call.receiver, call.method}
  	calls := cs.expected[key]
  	for i, c := range calls {
  		if c == call {
  			// maintain order for remaining calls
  			cs.expected[key] = append(calls[:i], calls[i+1:]...)
  			cs.exhausted[key] = append(cs.exhausted[key], call)
  			break
  		}
  	}
  }
docs: // Remove removes an expected call.