Note that the types that you can save to and restore from a Bundle are primitive types and classes that
implement the Serializable or Parcelable interfaces. It is usually a bad practice to put objects of
custom types into a Bundle, however, because the data might be stale when you get it back out. It is
a better choice to use some other kind of storage for the data and put a primitive identifier into the
What is the meaning of above sentence especially stale data, when using custom type.