code: function (args, callback) {
          if (ternserver) {
            ternserver.request({
                query: {
                  type: "rename",  //$NON-NLS-1$
                  file: args.meta.location,
                  end: args.params.offset,
                  newName: args.newname
                },
                files: args.files
              },
              function (error, changes) {
                if (error) {
                  callback({
                    request: 'rename',
                    error: typeof error === 'string' ? error : error.message,
                    message: Messages['failedRenameTern']
                  }); //$NON-NLS-1$
                } else if (changes && Array.isArray(changes.changes)) {
                  callback({request: 'rename', changes: changes}); //$NON-NLS-1$
                } else {
                  callback({request: 'rename', changes: []}); //$NON-NLS-1$
                }
              });
          } else {
            callback({request: 'rename', message: Messages['failedRenameNoServer']}); //$NON-NLS-1$
          }
        }
docs: /* rename message handler