private void addParentFeatures(@NotNull PsiElement element, @Nullable String tokenFeature, @NotNull String prefix) {
    if (!Registry.is("similarity.find.usages.use.parent.features")) {
      return;
    }
    PsiElement parent = element.getParent();
    if (parent != null) {
      myFeatures.add(tokenFeature + " " + prefix + " " + PsiUtilCore.getElementType(parent) + " " + getChildNumber(parent, element));
    }
  }
private void addParentFeatures(@NotNull PsiElement element, @Nullable String tokenFeature, @NotNull String prefix)