code: private static function getForeignKeysNames(string $table): array
      {
          if (self::$foreignKeysCache === null || !array_key_exists($table, self::$foreignKeysCache))
              self::getForeignKeys($table);
  
          return array_keys(self::$foreignKeysCache[$table]);
      }
docs: Get an array of the columns names of all FOREIGN KEY columns for the specified table.
  
  @param string $table The table name to inspect.
  @return array Returns an array of the column names of all FOREIGN KEYs of the specified table.
  @throws DatabaseConnectionException