code: public static boolean isInternalId(String schema) {
  
          String translatedId = translateLegacySystemId(schema);
          if (translatedId.startsWith(INTERNAL_SCHEME)) {
              return true;
          }
          return false;
      }
docs: Checks whether the given schema id is an internal schema id or is translated to an internal schema id.<p>
  @param schema the schema id
  @return true if the given schema id is an internal schema id or translated to an internal schema id