Stack (jems2 2.8.0 API)

All Known Implementing Classes:

EmptyStack, SingleStack, Topped
```
public interface Stack<Element>
```
An immutable stack. By design elements can only be retrieved from the top.

- Nested Class Summary
  
  Nested Classes
  Modifier and Type Interface Description
  
  static interface Stack.StackTop<Element>
  The top of a Stack.
- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  Optional<Stack.StackTop<Element>> top()
  Retrieves the top of this Stack.

- Method Detail
  - top
```
Optional<Stack.StackTop<Element>> top()
```
    Retrieves the top of this Stack. If the stack is empty the Stack.StackTop will be absent.