Software Design Patterns Assignment

$1.$ You will apply two patterns to example problems.

$2.$ The patterns must be iterator pattern and observer pattern.$($The subject of the iterator pattern is the music player system $,$ The subject of Observer Pattern is the live bourse tracking system$($USD$/$TRY $,$ EUR$/$TRY $,$ GAU$/$TRY $,$ BTC$/$TRY $...).)$

$3.$ You must explain why that pattern matches for that problem.

$4.$ Problem explanation, pattern UML diagram and how it works must be written on one A$4$ paper $($project report$)$

$5.$Use Java language