= false ) {
		return parent::supports_collation( $dbh_or_table );
	}

	/**
	 * Default implementation, calls wp_db appropriate method.
	 */
	public function default_has_cap( $db_cap, $dbh_or_table = false ) {
		return parent::has_cap( $db_cap, $dbh_or_table );
	}

	/**
	 * Default implementation, calls wp_db appropriate method.
	 */
	public function default_db_version( $dbh_or_table = false ) {
		return parent::db_version( $dbh_or_table );
	}

	/**
	 * Default implementation, calls wp_db appropriate method.
	 */
	public function switch_active_processor( $offset ) {
		$new_processor_number = $this->active_processor_number + $offset;
		if ( $new_processor_number <= 0 ) {
			$new_processor_number = 0;
		} else if ( $new_processor_number >= count( $this->processors ) ) {
				$new_processor_number = count( $this->processors ) - 1;
			}

		$offset_made = $new_processor_number - $this->active_processor_number;
		$this->active_processor_number = $new_processor_number;
		$this->active_processor = $this->processors[$new_processor_number];

		return $offset_made;
	}
}



/**
 * class CallUnderlying
 */
class _CallUnderlying {
	/**
	 * WPDB mixin.
	 *
	 * @var object
	 */
	private $wpdb_mixin;

	/**
	 * Constructor.
	 *
	 * @param object $manager Manager.
	 */
	function __construct( $manager ) {
		$this->wpdb_mixin = $manager;
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function initialize() {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->initialize();

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function flush() {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->flush();

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function query( $query ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->query( $query );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function _escape( $data ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->_escape( $data );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function prepare( $query, $args ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->prepare( $query, ...$args );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function insert( $table, $data, $format = null ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->insert( $table, $data, $format );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function replace( $table, $data, $format = null ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->replace( $table, $data, $format );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	/**
	 * Calls underlying processor's appropriate method of wp_db.
	 */
	function update( $table, $data, $where, $format = null, $where_format = null ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->update( $table, $data, $where, $format, $where_format );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}

	function delete( $table, $where, $where_format = null ) {
		$switched = $this->wpdb_mixin->switch_active_processor( 1 );

		try {
			$r = $this->wpdb_mixin->delete( $table, $where, $where_format );

			$this->wpdb_mixin->switch_active_processor( -$switched );
			return $r;
		} catch ( \Exception $e ) {
			$this->wpdb_mixin->switch_active_processor( -$switched );
			throw $e;
		}
	}
}