code: final List<Type> boundedVars() {
          return filterVars(uv -> uv.getBounds(InferenceBound.UPPER)
                   .diff(uv.getDeclaredBounds())
                   .appendList(uv.getBounds(InferenceBound.EQ, InferenceBound.LOWER)).nonEmpty());
      }
docs: Get list of bounded inference variables (where bound is other than
  declared bounds).