@Override
          public void visitXmlAttributeValue(@NotNull XmlAttributeValue value) {
            PsiReference ref = null;
            boolean skip = false;
            for (PsiReference reference : value.getReferences()) {
              if (reference instanceof TypeOrElementOrAttributeReference) {
                ref = reference;
              }
              else if (reference instanceof SchemaPrefixReference) {
                skip = true;
                break;
              }
            }
            if (!skip && ref != null) {
              final PsiElement xmlElement = ref.resolve();
              if (xmlElement instanceof XmlElement) {
                final XmlTag tag = PsiTreeUtil.getParentOfType(xmlElement, XmlTag.class, false);
                if (tag != null) {
                  if (tag.getNamespace().equals(namespace)) {
                    if (ref.getRangeInElement().getLength() == value.getValue().length()) { //no ns prefix
                      values.add(value);
                    }
                  }
                }
              }
            }
          }
@Override
          public void visitXmlAttributeValue(@NotNull XmlAttributeValue value)