GroupReference (Annot8 Core 0.2.0 API)

```
public interface GroupReference
```
A reference to a group.
This is a more lightweight object than the group.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`String`	`getGroupId()`	Get the id of the group which is referenced
`Optional<Group>`	`toGroup()`	Convert a reference to a group instance.
`static Stream<Group>`	`toGroups(Stream<GroupReference> references)`	Convert a stream of group references to groups

- Method Detail
  - toGroups
```
static Stream<Group> toGroups(Stream<GroupReference> references)
```
    Convert a stream of group references to groups
    
    Parameters:
    
    references - reference to convert (may be null)
    
    Returns:
    
    groups
  - getGroupId
```
String getGroupId()
```
    Get the id of the group which is referenced
    
    Returns:
    
    group id
  - toGroup
```
Optional<Group> toGroup()
```
    Convert a reference to a group instance.
    Since the group may have been deleted, this returns an optional.
    
    Returns:
    
    group corresponding to this reference (if it exists)