Add empty CopierTest class.
Add data classes for using them in unit-tests.
Change metadata tags to Copyable in test data class.
Body of "before" and "after" methods in CopierTest class.
Actualize method's name of ClonerTest class.
Add static method Copier.getCopyableFieldsForType() and tests for it.
Rename test data classes.
Rename local variables.
Rename properties in test class.
Add method Copier.copy() and tests for it.
Create shortcut package-level function dolly.clone() for Cloner.clone() method.
Create shortcut package-level function dolly.copy() for Copier.copy() method.