Source

File: wp-includes/Requests/IRI.php

public function __set($name, $value) {
		if (method_exists($this, 'set_' . $name)) {
			call_user_func(array($this, 'set_' . $name), $value);
		}
		elseif (
			   $name === 'iauthority'
			|| $name === 'iuserinfo'
			|| $name === 'ihost'
			|| $name === 'ipath'
			|| $name === 'iquery'
			|| $name === 'ifragment'
		) {
			call_user_func(array($this, 'set_' . substr($name, 1)), $value);
		}
	}