code: public static function table( $table_name ) {
  		global $wpdb;
  
  		if ( empty( self::$instances ) || empty( self::$instances[ $table_name ] ) ) {
  			self::$instances[ $table_name ] = new Query_Builder( $wpdb->prefix . $table_name );
  		}
  
  		return self::$instances[ $table_name ];
  	}
docs: Retrieve a Database instance by table name.
  
  @param string $table_name A Database instance id.
  
  @return Database Database object instance.