code: public int attrValCompare(Object val, String attrName,
                              boolean ignoreCase) throws NamingException {
      Attribute a = findAttr(attrName);
  
      if (a == null) {
        return -2;
      }
      return attrValCompare(val, a, ignoreCase);
    }
docs: Extract the target attribute from this record then
  compare the given single value with the attribute value(s).
  
  @param val
  @param attrName
  @param ignoreCase
  @return -2 for not equal or not present in multi-valued attribute
  -1 for val &lt; that
  0 for val = that
  1 for val &gt; that
  2 for val present in multi-valued attr
  @throws NamingException