given a new class-attribute pair. if the attribute already exists, the exisiting attribute(with possibly more childattributes) will be set as attribute of the class-attribute pair. The class of the class-attribute pair will be set as a root class, if the existing attribute was also a root class, attribute will be removed as root class but will remain as attribute of the new class.
added testcase for scenario 4:
A class already exists as class, but the new class-attribute pair has a new attribute. The attribute will be moved to the already existing class