QueryParameters.CommaSeparatedList C# (CSharp) Method

    public string CommaSeparatedList(string key)
    {
        if (parameterSet.ContainsKey(key))
        {
          var list = new StringBuilder(1000);
          string sep = "";
          foreach (string item in parameterSet[key])
          {
        list.Append(sep + item);
        sep = ",";
          }
          return list.ToString();
        }
        else
        {
          return "";
        }
    }