adds to null-objects

[TopMass99]

Here is my contribution. This is for a school project.
Adds a null object pattern.

[github-actions]

PR Summary

This PR implements the Null Object pattern. It adds a NullStudent class to handle cases where a student is not found, preventing null pointer exceptions. The Student class in the data-mapper module is modified, and new files are added for the null-objects module.

Changes

File	Summary
data-mapper/src/main/java/com/iluwatar/datamapper/Student.java	Added a constructor that throws UnsupportedOperationException. This change might be related to the Null Object pattern implementation.
leader-followers/src/main/java/com/iluwatar/leaderfollowers/App.java	Added license header to the file. No functional changes were made to the code.
null-objects/EnrolledStudent.java	New file. This class represents a student enrolled in a university. It stores the student's name and provides a getter method.
null-objects/Main.java	New file. This class demonstrates the Null Object pattern by retrieving students using University.getStudent(). It prints the names of the retrieved students.
null-objects/README.md	New file. This README explains the intent, explanation, example, and structure of the Null Object pattern implementation.
null-objects/Student.java	New file. This interface defines the common method getName() for Student classes.
null-objects/nullstudent	New file. This class implements the Student interface and represents a student who is not enrolled. Its getName() method returns "Not Enrolled in Student Database".

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[github-actions]

🚨 Pull request needs attention.

Review Summary

Commits Considered (1)

• 175c3f5: adds to null-objects

Files Processed (7)

• data-mapper/src/main/java/com/iluwatar/datamapper/Student.java (2 hunks)
• leader-followers/src/main/java/com/iluwatar/leaderfollowers/App.java (1 hunk)
• null-objects/EnrolledStudent.java (1 hunk)
• null-objects/Main.java (1 hunk)
• null-objects/README.md (1 hunk)
• null-objects/Student.java (1 hunk)
• null-objects/nullstudent (1 hunk)

Actionable Comments (1)

• null-objects/nullstudent [1-7]

  possible bug: "Missing Interface Implementation"

Skipped Comments (0)

[github-actions]

The NullStudent class should implement the Student interface to ensure consistent behavior. Currently, it's unclear what interface it's intended to implement.