private OptionalInt findImportMarker() {
      for (int token = 0; token < textLength; token = scanner.tokenEnd(token)) {
        if (text.startsWith("`import`", token)) {
          return OptionalInt.of(token);
        }
      }
      return OptionalInt.empty();
    }
{@inheritDoc} The result respects the Java syntax, whereby {@code Foo @Bar []} is an
annotation on the array type itself, while {@code @Bar Foo[]} would be an annotation on the
component type.
value/src/main/java/com/google/auto/value/processor/TypeEncoder.java