Fork or clone repository.

Implement and test the IItemRepository, ITagRepository, and IUserRepository interfaces using the rules from Assignment 03.

You must use an in-memory database and dependency injection for testing.

Recapitulate the meaning of encapsulation, inheritance, and polymorphism in object-oriented programming. Provide a description of these concepts including UML diagrams to illustrate your descriptions.

Draw a UML class diagram that illustrates your implementation of the entities of last week's C♯ assignment, see https://github.com/itu-bdsa/assignment-03/blob/main/README.md#kanban-board. The purpose of the diagram should be to document the main relationships between the entities and their multiplicities.

Draw a UML state diagram that illustrates your implementation of the WorkItem entity from last week's C♯ assignment, see https://github.com/itu-bdsa/assignment-03/blob/main/README.md#kanban-board. The purpose of the diagram should be to document the different states of the entity and the events that trigger the state changes.

For each of the five SOLID design principles, provide an example that illustrates the violation of the specific principle. Your examples can be given either in code or as UML diagrams. Briefly explain under which conditions the respective principle is violated. Note, the examples do not need to be sophisticated.

For each of the examples of violations of SOLID design principles in Exercise 4, provide a refactored design that respects the respective design principle. Again, the refactored designs can be given either in code or as UML diagrams, briefly explain under which conditions the respective principle is not violated any longer, and remember that the examples do not need to be sophisticated.

To submit the assignment you need to create a PDF document using LaTeX that contains the answers to the questions and a link to a public GitHub repository that contains a fork of the assignments repository with the completed code.

Note: You should not send a PR with your changes.

The PDF file must conform to the following naming convention: group_<x>_<id1>_<id2>_<id3>_assignment_04.pdf, where <x> is replaced by the number of your group from README_GROUPS.md and <id1>, <id2>, and <id3> are your respective ITU identifiers.

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