private CodeBlock optionalMethodBody(
        TypeMirror optionalType, PrettyPrintableKind printableKind) {
      return CodeBlock.builder()
          .addStatement(
              "return (value.isPresent() ? $L : $S)",
              format(CodeBlock.of("value.get()"), CodeBlock.of("indentLevel"), optionalType),
              printableKind.equals(PrettyPrintableKind.OPTIONAL) ? "<empty>" : "<absent>")
          .build();
    }
Parameter object to simplify the branches of {@link #format(CodeBlock, CodeBlock,
TypeMirror)} that call a delegate method.
value/src/main/java/com/google/auto/value/extension/toprettystring/processor/ToPrettyStringExtension.java