public function edge(Model $model = null)
    {
        return $this->finder->first($this->parent, $model, $this->type);
    }
public function edge(Model $model = null)
    {
        return $this->finder->first($this->parent, $model, $this->type);
    }
public function edge ( Model $ model = null ) { return $ this -> finder -> first ( $ this -> parent , $ model , $ this -> type ) ; }
Get the edge between the parent model and the given model or
the related model determined by the relation function name.

@param  \Illuminate\Database\Eloquent\Model $model
@return \Vinelab\NeoEloquent\Eloquent\Edges\Edge[In|Out]
Get the edge between the parent model and the given model or the related model determined by the relation function name .