title: Java interface not enforced
body: <p>I have the following class definition:</p>
  
  <pre><code>public class SyrianEdge extends BaseEdge&lt;SyrianVertex, SyrianEdge&gt; 
                          implements Weighted, Blockable{
      ...
  }
  </code></pre>
  
  <p>And the interface:</p>
  
  <pre><code>public interface Weighted{
      public long getWeight();
  }
  </code></pre>
  
  <p>The class SyrianEdge <strong>doesn't</strong> have the method <code>public long getWeight()</code> but everything seems to compile fine.</p>
  
  <p>What am I missing? How come the interface doesn't force the class to have its methods?</p>