title: How to mock new Date() in java using Mockito
body: <p>I have a function that uses the current time to make some calculations. I'd like to mock it using mockito.</p>
  
  <p>An example of the class I'd like to test:</p>
  
  <pre><code>public class ClassToTest {
      public long getDoubleTime(){
          return new Date().getTime()*2;
      }
  }
  </code></pre>
  
  <p>I'd like something like:</p>
  
  <pre><code>@Test
  public void testDoubleTime(){
     mockDateSomeHow(Date.class).when(getTime()).return(30);
     assertEquals(60,new ClassToTest().getDoubleTime());
  }
  </code></pre>
  
  <p>Is it possible to mock that? I wouldn't like to change the "tested" code in order to be tested.</p>