docs: private int getIntValue(int stackDepth, int defaultValue) {
          if (stack.getStackDepth() < stackDepth) {
              return defaultValue;
          }
          OpcodeStack.Item it = stack.getStackItem(stackDepth);
          Object value = it.getConstant();
          if (!(value instanceof Integer)) {
              return defaultValue;
          }
          return ((Number) value).intValue();
      }