Inject/Injector.php
public function get($key){
        if(isset($this->objects[$key])){
            return $this->objects[$key];
        }
        throw new InjectorException("obj $key not found");
    }
public function get($key){
        if(isset($this->objects[$key])){
            return $this->objects[$key];
        }
        throw new InjectorException("obj $key not found");
    }
get an object
@param $key
@return mixed
@throws InjectorException