docs: public EsRequest mappings( String type ) {
          EsRequest mappings = new EsRequest();
              EsRequest mappingsValue = new EsRequest();
                  EsRequest mtype = new EsRequest();
                      EsRequest properties = new EsRequest();       
                      for (EsIndexColumn col : columns()) {
                          properties.put(col.getName(), fieldMapping(col.getType()));
                          properties.put(col.getLowerCaseFieldName(), fieldMapping(PropertyType.STRING));
                          properties.put(col.getUpperCaseFieldName(), fieldMapping(PropertyType.STRING));
                          properties.put(col.getLengthFieldName(), fieldMapping(PropertyType.LONG));
                      }        
                  mtype.put("properties", properties);
              mappingsValue.put(type, mtype);
          mappings.put("mappings", mappingsValue);
          
          return mappings;
      }