QuickBooks/QBXML/Object/Check/ItemGroupLine.php
public function setItemGroupApplicationID($value)
	{
		return $this->set('ItemGroupRef ' . QUICKBOOKS_API_APPLICATIONID, $this->encodeApplicationID(QUICKBOOKS_OBJECT_ITEMGROUP, QUICKBOOKS_LISTID, $value));
	}
public function setItemGroupApplicationID($value)
	{
		return $this->set('ItemGroupRef ' . QUICKBOOKS_API_APPLICATIONID, $this->encodeApplicationID(QUICKBOOKS_OBJECT_ITEMGROUP, QUICKBOOKS_LISTID, $value));
	}
Set the primary key for the related record within your own application for the Check

@param mixed $value			The primary key within your own application
@return string