Make methods final where possible.

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/sequence/storage/MroSequenceStorage.java

@@ -85,7 +85,7 @@ public MroSequenceStorage(String className, int capacity) {
     }
 
     @Override
-    public PythonAbstractClass getItemNormalized(int idx) {
+    public final PythonAbstractClass getItemNormalized(int idx) {
         return values[idx];
     }
 
@@ -182,7 +182,7 @@ public Object[] getInternalArray() {
         return values;
     }
 
-    public PythonAbstractClass[] getInternalClassArray() {
+    public final PythonAbstractClass[] getInternalClassArray() {
         return values;
     }