var oldGroupToNewGroup = new Dictionary<int, int>();
[...blah...]
bool success = SketchWriter.ReadMemory(stream, brushGuids, bAdditive, out legacySketch, out oldGroupToNewGroup);
var oldGroupToNewGroup = new Dictionary<int, int>();
[...blah...]
bool success = SketchWriter.ReadMemory(stream, brushGuids, bAdditive, out legacySketch, out oldGroupToNewGroup);