Source

File: wp-includes/Requests/Hooks.php

public function dispatch($hook, $parameters = array()) {
		if (empty($this->hooks[$hook])) {
			return false;
		}

		foreach ($this->hooks[$hook] as $priority => $hooked) {
			foreach ($hooked as $callback) {
				call_user_func_array($callback, $parameters);
			}
		}

		return true;
	}