@Override
  public Set<PsiJavaFile> prepareOperation(UsageInfo @NotNull [] usages, @NotNull List<? extends @NotNull PsiElement> elements) {
    Set<PsiJavaFile> movedFiles = ContainerUtil.map2SetNotNull(elements, e -> ObjectUtils.tryCast(e.getContainingFile(), PsiJavaFile.class));
    return ContainerUtil.union(movedFiles, prepareOperation(usages));
  }
@Override
  public Set<PsiJavaFile> prepareOperation(UsageInfo @NotNull [] usages, @NotNull List<? extends @NotNull PsiElement> elements)