public static void onBeforeInsert(List newStockItems) {

        	//List for existing items
     	List<Stock_Item__c> existingStockItems = [SELECT Item_Name__c FROM Stock_Item__c];
        	for(Stock_Item__c esi : existingStockItems){
            	String existingStockItemName = esi.Item_Name__c;
       			}
            	system.debug('Number of Existing Items Pre-Insert'+ existingStockItems.size() );

        	//List for new items
		List<Stock_Item__c> newStockItems = [SELECT Item_Name__c FROM Stock_Item__c];
				for (Stock_Item__c si : newStockItems){
            	String newStockItemName = si.Item_Name__c;
                }
                system.debug('Number of New Stock Items'+ newStockItems.size() );
               	}

				//If there is already a Stock Item with that name, change the
					//name so that it is the name entered, plus the words “Duplicate Item”.
					//We have a process in place to check for these elsewhere.