classes/Container.php
protected function checkProtected($class, $alias)
	{
		if (!$this->protectInternals) {
			return;
		}

		if ($this->isProtected($class) || ($alias && $this->isProtected($alias))) {
			if ($alias) {
				$class = "$class (via alias $alias)";
			}
			$msg = "Class $class is internal and cannot be resolved.";
			throw new Exception\ResolvingInternalException($msg);
		}
	}
protected function checkProtected($class, $alias)
	{
		if (!$this->protectInternals) {
			return;
		}

		if ($this->isProtected($class) || ($alias && $this->isProtected($alias))) {
			if ($alias) {
				$class = "$class (via alias $alias)";
			}
			$msg = "Class $class is internal and cannot be resolved.";
			throw new Exception\ResolvingInternalException($msg);
		}
	}
Check if a class and its alias (optionally) are protected, and throw an
exception if they are.

@param  string $class
@param  string|null $alias

@return void

@throws Exception\ResolvingInternalException If class or alias is internal