original_string: public function get_unique_primary($table): ?string
    {
      if ( ($keys = $this->get_keys($table)) &&
        isset($keys['keys']['PRIMARY']) &&
        (\count($keys['keys']['PRIMARY']['columns']) === 1) ){
        return $keys['keys']['PRIMARY']['columns'][0];
      }
      return null;
    }
code: public function get_unique_primary($table): ?string
    {
      if ( ($keys = $this->get_keys($table)) &&
        isset($keys['keys']['PRIMARY']) &&
        (\count($keys['keys']['PRIMARY']['columns']) === 1) ){
        return $keys['keys']['PRIMARY']['columns'][0];
      }
      return null;
    }
code_tokens: public function get_unique_primary ( $ table ) : ? string { if ( ( $ keys = $ this -> get_keys ( $ table ) ) && isset ( $ keys [ 'keys' ] [ 'PRIMARY' ] ) && ( \ count ( $ keys [ 'keys' ] [ 'PRIMARY' ] [ 'columns' ] ) === 1 ) ) { return $ keys [ 'keys' ] [ 'PRIMARY' ] [ 'columns' ] [ 0 ] ; } return null ; }
docstring: Return the unique primary key of the given table.
  
  ```php
  \bbn\x::dump($db->get_unique_primary('table_users'));
  // (string) id
  ```
  
  @param string $table The table's name
  @return null|string
docstring_tokens: Return the unique primary key of the given table .