You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: Impedance.m
    path of file: ./repos/ELABorate/code/elements
    
    the code of the file until where you have to start completion: % Part of ELABorate, all rights reserved.
% Auth: Nicklas Vraa

classdef Impedance < Element
% A generic impedance clas
    
function obj = Impedance(id, anode, cathode, impedance)
        % Impedance object constructor. Impedance is optional.

            obj.id = id;
            obj.anode = anode;
            obj.cathode = cathode;
            obj.terminals = [obj.anode, obj.cathode];
            
            if isempty(impedance)
                obj.impedance = sym(id);
            else
                obj.impedance = sym(impedance);
            end