/// <summary>
 /// gets the value for the specified group and category
 /// </summary>
 /// <param name="category">the category name</param>
 /// <param name="group">the group name</param>
 /// <returns></returns>
 public double GetValue(string category, string group)
 {
     return(mDataSource.GetValue(category, group));
 }
 /// <summary>
 /// gets the value for the specified category
 /// </summary>
 /// <param name="category">the category name</param>
 /// <param name="group">the group name</param>
 /// <returns></returns>
 public double GetValue(string category)
 {
     return(mDataSource.GetValue(category, "Pie"));
 }