Source

File: wp-includes/Requests/Proxy/HTTP.php

public function __construct($args = null) {
		if (is_string($args)) {
			$this->proxy = $args;
		}
		elseif (is_array($args)) {
			if (count($args) == 1) {
				list($this->proxy) = $args;
			}
			elseif (count($args) == 3) {
				list($this->proxy, $this->user, $this->pass) = $args;
				$this->use_authentication = true;
			}
			else {
				throw new Requests_Exception('Invalid number of arguments', 'proxyhttpbadargs');
			}
		}
	}