void blockDataTypeRemoval(AbstractIntegerDataType dt) {
		long id = getID(dt);
		if (id == NULL_DATATYPE_ID) {
			throw new IllegalArgumentException(
				"Datatype instance is not associated with this manager");
		}
		if (blockedRemovalsByID == null) {
			blockedRemovalsByID = new HashSet<>();
		}
		blockedRemovalsByID.add(id);
	}
Register a {@link AbstractIntegerDataType}, during an invocation of 
{@link StructureDB#dataTypeDeleted(DataType)} or {@link UnionDB#dataTypeDeleted(DataType)},
to block final removal of the specified datatype since it is required for persistence of a 
defined bitfield. It is required that this be done within the same thread where this manager 
has initiated the removal and callbacks.
@param dt integer datatype which should be retained and not deleted
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java