@Override
  public XmlFile fromString(@Nullable @NonNls String s, @NotNull ConvertContext context) {
    if (s != null) {
      final GenericAttributeValue<XmlFile> element = (GenericAttributeValue<XmlFile>)context.getInvocationElement();
      final PsiReference[] references = createReferences(element, element.getXmlAttributeValue(), context);
      if (references.length > 0) {
        PsiElement result = references[references.length - 1].resolve();
        if (result instanceof XmlFile) {
          return (XmlFile)result;
        }
      }
    }
    return null;
  }
@Override
  public XmlFile fromString(@Nullable @NonNls String s, @NotNull ConvertContext context)