ObjectVersionReference (migration-utils 6.4.0 API)

```
public interface ObjectVersionReference
```
Represents a version of a Fedora 3 object. TODO: perhaps the audit trail should be parsed and exposed here

Author:

mdurbin

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`ObjectReference`	`getObject()`
`ObjectProperties`	`getObjectProperties()`
`String`	`getVersionDate()`
`int`	`getVersionIndex()`
`boolean`	`isFirstVersion()`
`boolean`	`isLastVersion()`
`List<DatastreamVersion>`	`listChangedDatastreams()`	Lists the current version of all datastreams changed from the pervious version to this one.
`boolean`	`wasDatastreamChanged(String dsId)`

- Method Detail
  - getObject
```
ObjectReference getObject()
```
    Returns:
    
    the ObjectReference object that encapsulates everything about the underlying Fedora 3 object.
  - getObjectProperties
```
ObjectProperties getObjectProperties()
```
    Returns:
    
    all the object properties. This is unversioned information.
  - getVersionDate
```
String getVersionDate()
```
    Returns:
    
    the lastModifiedDate proeperty for this version. This is formatted as all Fedora 3 dates are formatted.
  - listChangedDatastreams
```
List<DatastreamVersion> listChangedDatastreams()
```
    Lists the current version of all datastreams changed from the pervious version to this one.
    
    Returns:
    
    a List containing a DatastreamVersion for each datastream that changed from the last version to this one.
  - isLastVersion
```
boolean isLastVersion()
```
    Returns:
    
    true if this is the first version.
  - isFirstVersion
```
boolean isFirstVersion()
```
    Returns:
    
    true if this is the last version.
  - getVersionIndex
```
int getVersionIndex()
```
    Returns:
    
    the version index (0 for first, 1 for second, etc.) in chronological order from oldest to newest.
  - wasDatastreamChanged
```
boolean wasDatastreamChanged(String dsId)
```
    Parameters:
    
    dsId - of datastream to be tested for change.
    
    Returns:
    
    true if datastream with the given DSID changed as part of the update that contributed to this version.