transformClassDeclaration(tree) {
    let {
      elements,
      initStaticVars,
    } = this.transformClassElements_(tree);

    let superClass = this.transformAny(tree.superClass);
    let classDecl = new ClassDeclaration(tree.location, tree.name, superClass,
        elements, tree.annotations, tree.typeParameters);

    if (initStaticVars.length === 0) {
      return classDecl;
    }

    let statements =
        createStaticInitializerStatements(tree.name.identifierToken,
                                          initStaticVars);
    statements = prependStatements(statements, classDecl);

    return new AnonBlock(null, statements);
  }
Transforms a single class declaration

@param {ClassDeclaration} tree
@return {ParseTree}