Added part 4 materials

e7e7d788 · Juuso Rytilahti · f3059748 · e7e7d788 · e7e7d788 · e7e7d788
Commit e7e7d788 authored 1 year ago by Juuso Rytilahti
--- a/images/part-17/hierarchy2.PNG
+++ b/images/part-17/hierarchy2.PNG
--- a/images/part-17/hierarchy3.PNG
+++ b/images/part-17/hierarchy3.PNG
--- a/images/part-17/java-hierarchy.PNG
+++ b/images/part-17/java-hierarchy.PNG
--- a/images/part-17/wildcard-subtyping.PNG
+++ b/images/part-17/wildcard-subtyping.PNG
--- a/images/part-17/wildcard.PNG
+++ b/images/part-17/wildcard.PNG