code: function(folderName) {
                  if (typeof folderName !== 'string' || folderName.match(/[\\\/]/)) {
                      throw 'Sub folder name must be a valid string without delimiters.';
                  }
                  var subFolderPath = _path.join(_folderPath, folderName);
                  var subFolder = mod.createFolder(subFolderPath);
                  _subFolders[folderName] = subFolder;
  
                  return subFolder;
              }
docs: /*
  Adds a sub folder to the current folder.