Style guide

The Kotlin documentation includes the Coding Conventions topic. The most important rules of this topic are:

• Use Java conventions when in doubt
• Use four spaces for indention
• There's a space before and after a column when specifying a class and superclass, for example, class X : Y()
• There's no space when declaring variables, for example, val x: Int
• Do not specify the optional Unit return type for methods that do not return anything