@Override
  public @NotNull VirtualFile createChildFile(Object requestor, @NotNull VirtualFile parent, @NotNull String name) throws IOException {
    FSDir fsDir = convertDirectory(parent);
    if (fsDir.findChild(name) != null) throw new IOException("File " + name + " already exists in " + parent.getPath());
    fsDir.addChild(name, new FSFile());
    return new FakeVirtualFile(parent, name);
  }
@Override
  public @NotNull VirtualFile createChildFile(Object requestor, @NotNull VirtualFile parent, @NotNull String name)