blockquote>
When declaring a class, you can specify which, if any, <em>interfaces</em>
that the class implements. So, what's an interface? An interface declares
a set of methods and constants without specifying the implementation for
any of the methods. When a class claims to implement an interface, it's
claiming to provide implementations for all of the methods declared in the
interface.
<p>
To declare that your class implements an interface, use the keyword
<code>implements</code> followed by the interfac