A backwards incompatible change was introduced in 1.2.1 that forced LayoutWrapperEncoder to only be able to have a parent of type Appender.

Specifically, this change

 
This broke functionality in downstream projects that allow an encoder to be embedded with another encoder (specifically for prefix/suffix support).

 
It would be great if LayoutWrappingEncoder.setParent was changed to allow an Encoder or Appender as a parent, so that downstream projects can continue to allow encoders within other encoders.

I have submitted PR #383 to allow this.