morphMany through hasMany relations

Hello!

In my project I have Project which hasMany ServicesA and ServicesB and these services has morphMany Metrics. So basicly I would like get the Metrics for the projects through multiple models (ServicesA, ServicesB). What is the proper way to get all off the metrics for specific projects?

These are my models:

class Project extends Model
{
    public function serviceA()
    {
        return $this->hasMany(ServiceA::class);
    }

    public function serviceB()
    {
        return $this->hasMany(ServiceB::class);
    }

    public function metrics()
    {
        // ???
    }
}

class ServiceA extends Model
{
    public function project()
    {
        return $this->belongsTo(Project::class);
    }

    public function metrics()
    {
        return $this->morphMany(Metric::class, 'servicable');
    }
}
class ServiceB extends Model
{
    public function project()
    {
        return $this->belongsTo(Project::class);
    }

    public function metrics()
    {
        return $this->morphMany(Metric::class, 'servicable');
    }
}

class Metric extends Model
{
    public function monitor()
    {
        return $this->morphTo('servicable');
    }
}