public String getEmpty() {
    String empty = className.startsWith("java.util.") ? ".empty()" : ".absent()";
    return TypeEncoder.encodeRaw(optionalType) + empty;
  }
Returns a string representing the method call to obtain the empty version of this Optional.
This will be something like {@code "Optional.empty()"} or possibly {@code
"java.util.Optional.empty()"}. It does not have a final semicolon.

<p>This method is public so that it can be referenced as {@code p.optional.empty} from
templates.
value/src/main/java/com/google/auto/value/processor/Optionalish.java