/**
  * @test
  */
 public function is_sub_item_collection()
 {
     $structureItemCollection = array(new StructureItem('b', StructureDefinition::STRING), new StructureItem('a.b', StructureDefinition::HASHTABLE), new StructureItem('a', StructureDefinition::HASHTABLE), new StructureItem('a.b.c', StructureDefinition::STRING));
     $structureDefinition = new StructureDefinition($structureItemCollection);
     $aStructureItem = new StructureItem('a', StructureDefinition::HASHTABLE);
     $subItemCollection = $structureDefinition->subStructureItemsOf($aStructureItem);
     $this->assertEquals(2, count($subItemCollection));
     foreach ($subItemCollection as $subStructureItem) {
         $this->assertTrue($subStructureItem->isSubItemOf($aStructureItem));
     }
 }