Introduction In episode 9, Miki discussed how a command flag can be decoded into a user defined type with the Value interface. As a recap, the Value interface consists of two methods: one for serializing the underlying concrete type and one for deserializing a string into an object. To put this interface to the test, Miki wrote a command that had a flag to specify a network address. While implementing the Set method of the Value interface, Miki demonstrated how to add validation for your program’s flags.