code: public I_CmsXmlContentValue addValue(CmsObject cms, I_CmsXmlSchemaType type, int index) {
  
          String xpath = CmsXmlUtils.concatXpath(CmsXmlUtils.removeLastXpathElement(getPath()), type.getName());
          return addValue(cms, xpath, index);
      }
docs: Adds a value element of the given type
  at the selected index to the XML content document.<p>
  
  @param cms the current users OpenCms context
  @param type the type to add
  @param index the index where to add the new value element
  
  @return the added XML content value element
  
  @see CmsXmlContent#addValue(CmsObject, String, Locale, int)
  @see #addValue(CmsObject, String, int)
  @see #addValue(CmsObject, int)