Source

File: wp-includes/Requests/Transport/fsockopen.php

protected static function format_get($url_parts, $data) {
		if (!empty($data)) {
			if (empty($url_parts['query'])) {
				$url_parts['query'] = '';
			}

			$url_parts['query'] .= '&' . http_build_query($data, null, '&');
			$url_parts['query'] = trim($url_parts['query'], '&');
		}
		if (isset($url_parts['path'])) {
			if (isset($url_parts['query'])) {
				$get = $url_parts['path'] . '?' . $url_parts['query'];
			}
			else {
				$get = $url_parts['path'];
			}
		}
		else {
			$get = '/';
		}
		return $get;
	}