@Nullable
  private static String resolveXmlElement(@Nullable XmlElement xmlElement) {
    if (xmlElement == null) return null;

    MavenPropertyPsiReference psiReference = findInstance(xmlElement.getReferences(), MavenPropertyPsiReference.class);
    if (psiReference == null) return null;

    PsiElement resolvedElement = psiReference.resolve();
    if (!(resolvedElement instanceof MavenPsiElementWrapper)) return null;

    PsiElement xmlTag = ((MavenPsiElementWrapper)resolvedElement).getWrappee();
    if (!(xmlTag instanceof XmlTag)) return null;

    return ((XmlTag)xmlTag).getValue().getTrimmedText();
  }
@Nullable
  private static String resolveXmlElement(@Nullable XmlElement xmlElement)