| Class names from `java.lang` should never be reused. From |
| [Java Puzzlers](http://www.javapuzzlers.com/java-puzzlers-sampler.pdf): |
| |
| > Avoid reusing the names of platform classes, and never reuse class names from |
| > `java.lang`, because these names are automatically imported everywhere. |
| > Programmers are used to seeing these names in their unqualified form and |
| > naturally assume that these names refer to the familiar classes from |
| > `java.lang`. If you reuse one of these names, the unqualified name will refer |
| > to the new definition any time it is used inside its own package. |
