public function addFile($fileName)
    {
        $this->files[$fileName] = sha1_file($fileName);

        $reflection = new FileReflector($fileName, true);
        $reflection->process();

        foreach ($reflection->getClasses() as $class) {
            $class = new ClassDoc($class, $this, ['sourceFile' => $fileName]);
            $this->classes[$class->name] = $class;
        }
        foreach ($reflection->getInterfaces() as $interface) {
            $interface = new InterfaceDoc($interface, $this, ['sourceFile' => $fileName]);
            $this->interfaces[$interface->name] = $interface;
        }
        foreach ($reflection->getTraits() as $trait) {
            $trait = new TraitDoc($trait, $this, ['sourceFile' => $fileName]);
            $this->traits[$trait->name] = $trait;
        }
    }