code: private RDBMetadata extractDBMetadata(SQLPPMapping ppMapping, Optional<RDBMetadata> optionalDBMetadata,
                                            OBDASpecInput specInput)
              throws DBMetadataExtractionException {
  
          boolean isDBMetadataProvided = optionalDBMetadata.isPresent();
  
          /*
           * Metadata extraction can be disabled when DBMetadata is already provided
           */
          if (isDBMetadataProvided && (!settings.isProvidedDBMetadataCompletionEnabled()))
              return optionalDBMetadata.get();
  
          try (Connection localConnection = LocalJDBCConnectionUtils.createConnection(settings)) {
              return isDBMetadataProvided
                      ? dbMetadataExtractor.extract(ppMapping, localConnection, optionalDBMetadata.get(),
                      specInput.getConstraintFile())
                      : dbMetadataExtractor.extract(ppMapping, localConnection, specInput.getConstraintFile());
          }
          /*
           * Problem while creating the connection
           */
          catch (SQLException e) {
              throw new DBMetadataExtractionException(e.getMessage());
          }
      }
docs: Makes use of the DB connection