code: public MarkLogicNode getContentAsMarkLogicNode() {
          if (contentType == ContentType.XML || 
              contentType == ContentType.TEXT) {
              return new MarkLogicNode(getContentAsText().toString(), 
                              contentType);      
          }
          throw new UnsupportedOperationException(
              "Cannot convert JSON or binary data to MarkLogicNode.");        
      }
docs: /* (non-Javadoc)
  @see com.marklogic.mapreduce.MarkLogicDocument#getContentAsMarkLogicNode()