//The keys
List<T> keys = new ArrayList<T>( mappings.getMappings().keySet() );
Collections.sort( keys, comparator );
for ( T key : keys ) {
VersionMapping mapping = mappings.getMapping( key );
List<Version> versions = new ArrayList<Version>();
for ( Version keyVersion : keyVersions ) {
versions.add( mapping.resolveVersion( keyVersion ) );
}
columns.add( new Column( toString.convert( key ), versions ) );
}