public function start() {
		global $wpdb, $wp_object_cache;
		$this->start_time   = microtime( true );
		$this->query_offset = ! empty( $wpdb->queries ) ? count( $wpdb->queries ) : 0;
		if ( false === ( $key = array_search( $this, self::$active_loggers ) ) ) {
			self::$active_loggers[] = $this;
		}
		$this->cache_hit_offset  = ! empty( $wp_object_cache->cache_hits ) ? $wp_object_cache->cache_hits : 0;
		$this->cache_miss_offset = ! empty( $wp_object_cache->cache_misses ) ? $wp_object_cache->cache_misses : 0;
	}