Version { public boolean isEmpty(){ return union == 0; } Version(); private  Version(long union);  Version(final Action action);  Version(final Integer index);  Version(final Date dateTime); static Version valueOf(long union); boolean isEmpty(); boolean isVersionAction(); long union(); Action getVersionAction(); boolean isIndex(); Integer getIndex(); boolean isDateTime(); Date getDateTime(); @Override boolean equals(Object o); @Override int hashCode();  }
@Test public void versionEmpty() { Version version = new Version(); assertTrue(version.isEmpty()); }