public void enterMulti(Multi term) {
   if (term.isNegation()) mLdapFilter.append("(!");
   if (term.getTerms().size() > 1) {
     if (term.isAnd()) mLdapFilter.append("(&");
     else mLdapFilter.append("(|");
   }
 }
 public void leaveMulti(Multi term) {
   if (term.getTerms().size() > 1) mLdapFilter.append(')');
   if (term.isNegation()) mLdapFilter.append(')');
 }