2 Checks for use of `Box<T>` where T is a collection such as Vec anywhere in the code.
3 Check the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information.
6 Collections already keeps their contents in a separate area on
7 the heap. So if you `Box` them, you just add another level of indirection
8 without any benefit whatsoever.
13 values: Box<Vec<Foo>>,