class function TStringHelper.Join(const Separator: string; const Values: array of string): string;
begin
  Result := Join(Separator, Values, 0, System.Length(Values));
end;

class function TStringHelper.Join(const Separator: string; const Values: array of string; StartIndex,
  Count: Integer): string;
var
  I: Integer;
  Max: Integer;
begin
  if (Count = 0) or ((System.Length(Values) = 0) and (StartIndex = 0)) then
    Result := ''
  else
  begin
    if (Count < 0) or (StartIndex >= System.Length(Values)) then
      raise ERangeError.CreateRes(@SRangeError);

    if (StartIndex + Count) > System.Length(Values) then
      Max := System.Length(Values)
    else
      Max := StartIndex + Count;

    Result := Values[StartIndex];
    for I:= StartIndex + 1 to Max - 1 do
      Result := Result + Separator + Values[I];
  end;
end;