protected static Step asStep(ProcessingStep processingStep) {
    return new ProcessingStepAsStep(processingStep);
  }
Wraps the passed {@link ProcessingStep} in a {@link Step}. This is a convenience method to
allow incremental migration to a String-based API. This method can be used to return a not yet
converted {@link ProcessingStep} from {@link BasicAnnotationProcessor#steps()}.
common/src/main/java/com/google/auto/common/BasicAnnotationProcessor.java