public function put($relationship, $model)
 {
     if ($model != null && is_a($model, 'SpectrumModel')) {
         if (is_a($relationship, 'SpectrumParentRelationship')) {
             if (!array_key_exists($relationship->relationshipName, $this->parents)) {
                 $this->parents[$relationship->relationshipName] = $model;
             }
         } else {
             if (is_a($relationship, 'SpectrumChildRelationship')) {
                 if (!array_key_exists($relationship->relationshipName, $this->children)) {
                     $this->children[$relationship->relationshipName] = SpectrumCollection::forge($relationship->modelType);
                 }
                 $this->children[$relationship->relationshipName]->put($model);
             }
         }
     }
 }
 public function fetchCollection()
 {
     $entities = $this->fetch();
     return SpectrumCollection::forge($this->modelType, null, $entities);
 }