@Deprecated
  protected Iterable<? extends ProcessingStep> initSteps() {
    throw new AssertionError("If steps() is not implemented, initSteps() must be.");
  }
Creates {@linkplain ProcessingStep processing steps} for this processor. {@link #processingEnv}
is guaranteed to be set when this method is invoked.

@deprecated Implement {@link #steps()} instead.
common/src/main/java/com/google/auto/common/BasicAnnotationProcessor.java