internal override int Compare(SafeHandle ld, string dn, string attr, string value, IntPtr bvalue,
IntPtr serverctrls, IntPtr clientctrls,
ref int msgidp)
{
var ptr = bvalue == IntPtr.Zero && value != null ? StringToBerVal(value) : bvalue;
return NativeMethodsOsx.ldap_compare_ext(ld, dn, attr, ptr, serverctrls, clientctrls, ref msgidp);
}