src/language-js/print/class.js/printClassBody
function printClassBody(path, options, print) {
  const n = path.getValue();
  if (!hasComment(n) && n.body.length === 0) {
    return "{}";
  }

  return concat([
    "{",
    n.body.length > 0
      ? indent(
          concat([
            hardline,
            path.call((bodyPath) => {
              return printStatementSequence(bodyPath, options, print);
            }, "body"),
          ])
        )
      : printDanglingComments(path, options),
    hardline,
    "}",
  ]);
}