code: @Override
      public void visitClassContext(ClassContext classContext) {
          try {
              isEnum = classContext.getJavaClass().isEnum();
              stack = new OpcodeStack();
              uninitializedRegs = new BitSet();
              arrayAliases = new HashMap<>();
              storedUVs = new HashMap<>();
              super.visitClassContext(classContext);
          } finally {
              stack = null;
              uninitializedRegs = null;
              arrayAliases = null;
              storedUVs = null;
          }
      }
docs: overrides the visitor to reset the stack
  
  @param classContext
  the context object of the currently parsed class