internal DBConnectionString Intersect(DBConnectionString entry)
        {
            KeyRestrictionBehavior behavior = _behavior;
            string[] restrictionValues = null;

            if (null == entry)
            {
                //Debug.WriteLine("0 entry AllowNothing");
                behavior = KeyRestrictionBehavior.AllowOnly;
            }
            else if (this._behavior != entry._behavior)
            { // subset of the AllowOnly array
                behavior = KeyRestrictionBehavior.AllowOnly;

                if (KeyRestrictionBehavior.AllowOnly == entry._behavior)
                { // this PreventUsage and entry AllowOnly
                    if (!ADP.IsEmptyArray(_restrictionValues))
                    {
                        if (!ADP.IsEmptyArray(entry._restrictionValues))
                        {
                            //Debug.WriteLine("1 this PreventUsage with restrictions and entry AllowOnly with restrictions");
                            restrictionValues = NewRestrictionAllowOnly(entry._restrictionValues, _restrictionValues);
                        }
                        else
                        {
                            //Debug.WriteLine("2 this PreventUsage with restrictions and entry AllowOnly with no restrictions");
                        }
                    }
                    else
                    {
                        //Debug.WriteLine("3/4 this PreventUsage with no restrictions and entry AllowOnly");
                        restrictionValues = entry._restrictionValues;
                    }
                }
                else if (!ADP.IsEmptyArray(_restrictionValues))
                { // this AllowOnly and entry PreventUsage
                    if (!ADP.IsEmptyArray(entry._restrictionValues))
                    {
                        //Debug.WriteLine("5 this AllowOnly with restrictions and entry PreventUsage with restrictions");
                        restrictionValues = NewRestrictionAllowOnly(_restrictionValues, entry._restrictionValues);
                    }
                    else
                    {
                        //Debug.WriteLine("6 this AllowOnly and entry PreventUsage with no restrictions");
                        restrictionValues = _restrictionValues;
                    }
                }
                else
                {
                    //Debug.WriteLine("7/8 this AllowOnly with no restrictions and entry PreventUsage");
                }
            }
            else if (KeyRestrictionBehavior.PreventUsage == this._behavior)
            { // both PreventUsage
                if (ADP.IsEmptyArray(_restrictionValues))
                {
                    //Debug.WriteLine("9/10 both PreventUsage and this with no restrictions");
                    restrictionValues = entry._restrictionValues;
                }
                else if (ADP.IsEmptyArray(entry._restrictionValues))
                {
                    //Debug.WriteLine("11 both PreventUsage and entry with no restrictions");
                    restrictionValues = _restrictionValues;
                }
                else
                {
                    //Debug.WriteLine("12 both PreventUsage with restrictions");
                    restrictionValues = NoDuplicateUnion(_restrictionValues, entry._restrictionValues);
                }
            }
            else if (!ADP.IsEmptyArray(_restrictionValues) && !ADP.IsEmptyArray(entry._restrictionValues))
            { // both AllowOnly with restrictions
                if (this._restrictionValues.Length <= entry._restrictionValues.Length)
                {
                    //Debug.WriteLine("13a this AllowOnly with restrictions and entry AllowOnly with restrictions");
                    restrictionValues = NewRestrictionIntersect(_restrictionValues, entry._restrictionValues);
                }
                else
                {
                    //Debug.WriteLine("13b this AllowOnly with restrictions and entry AllowOnly with restrictions");
                    restrictionValues = NewRestrictionIntersect(entry._restrictionValues, _restrictionValues);
                }
            }
            else
            { // both AllowOnly
                //Debug.WriteLine("14/15/16 this AllowOnly and entry AllowOnly but no restrictions");
            }

            // verify _hasPassword & _parsetable are in sync between Everett/Whidbey
            Debug.Assert(!_hasPassword || ContainsKey(KEY.Password) || ContainsKey(KEY.Pwd), "OnDeserialized password mismatch this");
            Debug.Assert(null == entry || !entry._hasPassword || entry.ContainsKey(KEY.Password) || entry.ContainsKey(KEY.Pwd), "OnDeserialized password mismatch entry");

            DBConnectionString value = new DBConnectionString(this, restrictionValues, behavior);
            ValidateCombinedSet(this, value);
            ValidateCombinedSet(entry, value);

            return value;
        }