/// This method create single instance of this class and returns the same instance in the subsequent class.
 public static CustomMapping GetInstance()
 {
     lock (_lock)
     {
         if (_instance == null)
         {
             _instance = new CustomMapping();
             _instance.RegisterMappings();
         }
         return(_instance);
     }
 }
 public BusinessBase()
 {
     _db            = new EMDBContext();
     _CustomMapping = CustomMapping.GetInstance();
 }