public @NotNull DomExtension registerFixedNumberChildrenExtension(final @NotNull XmlName name, final @NotNull Type type, final int count) {
    assert count > 0;
    return addExtension(myFixeds, name, type).setCount(count);
  }
public @NotNull DomExtension registerFixedNumberChildrenExtension(final @NotNull XmlName name, final @NotNull Type type, final int count)