protected void checkAncestry(DataType dataType) throws IllegalArgumentException {
		if (this.equals(dataType)) {
			throw new IllegalArgumentException(
				"Data type " + getDisplayName() + " can't contain itself.");
		}
		else if (DataTypeUtilities.isSecondPartOfFirst(dataType, this)) {
			throw new IllegalArgumentException("Data type " + dataType.getDisplayName() + " has " +
				getDisplayName() + " within it.");
		}
	}
This method throws an exception if the indicated data type is an ancestor of
this data type (i.e., the specified data type has a component or
sub-component containing this data type).

@param dataType the data type
@throws IllegalArgumentException if the data type is an ancestor of this data
                                 type.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/CompositeDataTypeImpl.java