code: void save(final ZipUTF8Writer writer) throws IOException {
          this.odsElements.createEmptyElements(writer);
          this.odsElements.writeImmutableElements(this.xmlUtil, writer);
          this.odsElements.writeMeta(this.xmlUtil, writer);
          this.odsElements.writeStyles(this.xmlUtil, writer);
          this.odsElements.writeContent(this.xmlUtil, writer);
          this.odsElements.writeSettings(this.xmlUtil, writer);
          this.logger.log(Level.FINE, "file saved");
      }
docs: Saves a file.
  Do not close the writer (see https://github.com/jferard/fastods/issues/138)
  
  @param writer where to write
  @throws IOException if the document can't be saved