code: public function onLoadDataContainer($tableName)
      {
          static $tableExists;
          // Test that the tables have been created.
          if (null === $tableExists) {
              $tableExists = \System::getContainer()
                  ->get('database_connection')
                  ->getSchemaManager()
                  ->tablesExist(['tl_metamodel']);
          }
          if (false === $tableExists) {
              return;
          }
  
          $this->handleMetaModelTable($tableName);
          $this->handleNonMetaModelTable($tableName);
      }
docs: Load a data container.
  
  @param string $tableName The table name.
  
  @return void