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: cgpot.m
    path of file: ./repos/bnt/BNT/potentials/@cgpot
    
    the code of the file until where you have to start completion: function pot = cgpot(ddom, cdom, node_sizes, can, mom, subtype)
% CPOT Make a canonical CG potential.
% function pot = cgpot(ddom, cdom, node_sizes, can, mom, subtype)
%
% node_sizes(i) is the size of the i'th node.

    
function pot = cgpot(ddom, cdom, node_sizes, can, mom, subtype)
% CPOT Make a canonical CG potential.
% function pot = cgpot(ddom, cdom, node_sizes, can, mom, subtype)
%
% node_sizes(i) is the size of the i'th node.
% can and mom default to 0s.
% subtype defaults to 'c'.

if nargin < 6, subtype = 'c'; end