public function query( $query ) {
		if ( ! $this->ready ) {
			if ( isset( $this->check_current_query ) ) {
				// This property was introduced in WP 4.2
				$this->check_current_query = true;
			}
			return false;
		}

		if ( $this->show_errors ) {
			$this->hide_errors();
		}

		$result = parent::query( $query );

		if ( ! SAVEQUERIES ) {
			return $result;
		}

		$i = $this->num_queries - 1;
		$this->queries[ $i ]['trace'] = new QM_Backtrace( array(
			'ignore_frames' => 1,
		) );

		if ( ! isset( $this->queries[ $i ][3] ) ) {
			$this->queries[ $i ][3] = $this->time_start;
		}

		if ( $this->last_error ) {
			$code = 'qmdb';
			if ( $this->use_mysqli ) {
				if ( $this->dbh instanceof mysqli ) {
					$code = mysqli_errno( $this->dbh );
				}
			} else {
				if ( is_resource( $this->dbh ) ) {
					// Please do not report this code as a PHP 7 incompatibility. Observe the surrounding logic.
					// @codingStandardsIgnoreLine
					$code = mysql_errno( $this->dbh );
				}
			}
			$this->queries[ $i ]['result'] = new WP_Error( $code, $this->last_error );
		} else {
			$this->queries[ $i ]['result'] = $result;
		}

		return $result;
	}