code: public JsonWriter openSquareBracket() throws IOException {
          if (!willWriteValue) {
              indent();
          }
          writer.write("[");
          nextLine();
          indentDepth++;
          willWriteValue = false;
          return this;
      }
docs: Open a single square bracket.
  
  @return this JsonWriter
  @throws IOException if an I/O error has occurred