use Any
use Option

```doc
# Modulus

Values which wish to implement the `%` infix operator must implement this protocol.
```
protocol Modulus, as: do
  ```doc
  Divide `self` by `other`, returning an option containing the remainder

  It is left up to the implementer to define when it should return `Some` or `None`.
  ```
  def modulo(self: Self, other: Any): Option
end