MappingElement

All Known Implementing Classes:

ExpressionMappingElement, StaticValueMappingElement
```
public interface MappingElement
```

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`shutdown()`
`java.util.Optional<QualifiedValue>`	`startup(java.util.function.Consumer<QualifiedValue> listener)`	Start up the mapping element.

- Method Detail
  - startup
```
java.util.Optional<QualifiedValue> startup(java.util.function.Consumer<QualifiedValue> listener)
```
    Start up the mapping element.
    
    Parameters:
    
    listener - If this mapping element's value changes in the future, it will invoke this listener.
    
    Returns:
    
    An optional qualified value that represents the initial value of the element if it is available synchronously during startup. An element that returns a non-empty value here may never invoke the listener.
  - shutdown
```
void shutdown()
```