private static PsiReference[] getLocationReferences(String namespace, XmlTag tag) {
    XmlAttribute locationAttr = tag.getAttribute(XmlUtil.SCHEMA_LOCATION_ATT, XmlUtil.XML_SCHEMA_INSTANCE_URI);
    if (locationAttr == null) {
      return PsiReference.EMPTY_ARRAY;
    }
    XmlAttributeValue value = locationAttr.getValueElement();
    return value == null ? PsiReference.EMPTY_ARRAY : getLocationReferences(namespace, value);
  }
private static PsiReference[] getLocationReferences(String namespace, XmlTag tag)