public void operations(String operation,Integer parameter,Book book){
		
        if(operation.equals("Add")){
        	//Add Operation needs to be executed immediately. It need not be queued up. Hence execute is called from here itself. This also acts as an invoker of the command pattern.
        	//Add Operation requires a sequence of steps to be executed. Hence Command is used.
        	new AddOperation(book).execute();
        }
        else if(operation.equals("Delete")){
        	  //Delete Operation needs to be just queued up here
              OperationRequestor.deleteBooks.add(parameter);
              or.addOperation(new DeleteOperation(parameter));
        }
        else if(operation.equals("Request")){
        	 //Request Operation needs to be just queued up here
        	 or.addOperation(new RequestOperation(parameter));
        	 OperationRequestor.requestBooks.add(parameter);
        }
        else if((operation.equals("availability")||(operation.equals("borrower")))){
        	//Update Operation needs to be executed immediately. It need not be queued up. Hence execute is called from here itself. This also acts as an invoker of the command pattern.
        	//Update Operation requires a sequence of steps to be executed. Hence Command is used.
        	new UpdateOperation(operation,parameter).execute();
        }
	}