Java PowerMockito Mocking Instant.now()
<p>I'm attempting to Mock the static method <code>Instant.now()</code> and I continue to keep coming across weird behavior when trying to mock classes from <code>java.time</code> package. Please see my code below on attempting to mock <code>Instant.now()</code></p>

<pre><code>@RunWith(PowerMockRunner.class)
@PrepareForTest(Instant.class)
public class UnitTestClasss {
    @Test
    public void unitTestMethod() throws Exception {
        mockCurrentTimeAtMidNight();
        instanceOfSystemUnderTest.someMethodDependingOnTime();
        assertHandledHere();
    }

    /*See First Error Below */
    private void mockCurrentTimeAtMidNight() {
        ZonedDateTime current = ZonedDateTime.now();
        ZonedDateTime mockMidNight = ZonedDateTime.of(current.getYear(), current.getMonthValue(),
                current.getDayOfMonth(), 0, 0, 0, 0,current.getZone());

        PowerMockito.mockStatic(Instant.class);
        PowerMockito.when(Instant.now()).thenReturn(Instant.from(mockMidNight));
    }

    /*See Second Error Below */
    private void mockCurrentTimeAtMidNight2() {
        Calendar cal = Calendar.getInstance();

        ZonedDateTime mockMidNight = ZonedDateTime.of(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH),
                cal.get(Calendar.DAY_OF_MONTH), 0, 0, 0, 0,ZoneId.of("US/Eastern"));
        Instant instant = mockMidNight.toInstant();
        PowerMockito.mockStatic(Instant.class);
        PowerMockito.when(Instant.now()).thenReturn(instant);
    }

}
</code></pre>

<blockquote>
  <p>Errors 1
  org.mockito.exceptions.misusing.UnfinishedStubbingException: 
      Unfinished stubbing detected here:
      -> at org.powermock.api.mockito.PowerMockito.when(PowerMockito.java:495)</p>

<pre><code>E.g. thenReturn() may be missing.
Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();
Hints:
 1. missing thenReturn()
 2. you are trying to stub a final method, you naughty developer!
 3: you are stubbing the behaviour of another mock inside before 'thenReturn' instruction if completed
</code></pre>
  
  <p>Errors 2: with Reason: [source error] <code>toInstant()</code> not found in
  <code>java.time.ZonedDateTime</code></p>
</blockquote>