public function filter_http_request_args( array $args, $url ) {
		$trace = new QM_Backtrace();
		if ( isset( $args['_qm_key'] ) ) {
			// Something has triggered another HTTP request from within the `pre_http_request` filter
			// (eg. WordPress Beta Tester does this). This allows for one level of nested queries.
			$args['_qm_original_key'] = $args['_qm_key'];
			$start                    = $this->data['http'][ $args['_qm_key'] ]['start'];
		} else {
			$start = microtime( true );
		}
		$key                        = microtime( true ) . $url;
		$this->data['http'][ $key ] = array(
			'url'   => $url,
			'args'  => $args,
			'start' => $start,
			'trace' => $trace,
		);
		$args['_qm_key']            = $key;
		return $args;
	}