public static bool Equals(SpecializationKey obj1, SpecializationKey obj2)
        {
            if (Object.Equals(null, obj1) || Object.Equals(null, obj2))
                return false;

            return obj1.SpecializationType == obj2.SpecializationType
                && obj1.FileType == obj2.FileType;  
        }
 public SpecializationNotFoundException(SpecializationKey key)
     : base(string.Format("Could not find specialization for {0}:{1}", key.SpecializationType, key.FileType))
 {
     
 }
 public bool Equals(SpecializationKey other)
 {
     return Equals(this, other);
 }