Need help with #5

S IS 4. What is a pull request, and what is its role in a project with a team cof Why is a problem that in the built in Observer/Observable APl, the observable class must extend the abstract class Observable rather than i interface as in the Headfirst version of the pattern that we looked at in class? 5. 5 6. In Git or other version control systems, what is the purpose of a branch? (5) want to develoo tne Same Code basc n new eadures Branchiny lcts au do tis u (Ses (+ more extensive(