Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
Q: The Law of Demeter ('talk only to your friends') is a good place to start, but think about it this way: you can play with your toys, with toys that you make, and with toys that someone gives you. You don't ever, ever play with your toy's toys. Source: The Thoughtworks Anthology What could the last sentence mean? Could a toy have a toy? Assuming a toy means 'A toy is an item that is used in play', a toy can never have a toy, so one cannot play with a toy's toys (it's physically not possible). The context is object oriented programming.
A: 
Toys absolutely can have toys. For example, this 'Barbie Kelly Playroom' comes with stuffed animals, dolls, a play kitchen, and UNO for Kelly (Barbie's sister and a toy): In this case, it would be possible to play with Kelly's toys directly (with the exception of UNO, which is almost certainly just a box). However, what you're supposed to do is have Kelly play with her toys.