code: public JSONWriter objectItem(String name) throws IOException {
          beforeObjectItem();
  
          writer.write(JSON.QUOTE);
          writer.write(escape(name));
          writer.write(JSON.QUOTE);
          writer.write(JSON.COLON);
          return this;
      }
docs: object item.
  
  @param name name.
  @return this.
  @throws IOException.