strict - whether the IDs will be compared strictly or not
public DBObjectIDMultiMap(boolean strict,
Constructs a new map that is optionally concurrent (i.e. thread safe).
Choosing to make the map thread safe when it isn't required means the
map will be slower than it needs to be. The DBObjectID keys will
optionally be compared strictly.
strict - whether the keys will be compared strictly
concurrent - whether the map and its contained Collection values
should be thread safe.