Pit Mutation Testing Conditionals - if/else failing - Java

So I have build a programing using AWS Java SDK and I'm in the process of writing the JUnit tests for them. No matter what I do I cannot see how to kill these mutations.

I have the following:

    class A{
    List<String> aList;
    getter for aList;
    setter for aList;

    private ClassB daoClass;

    public boolean initializeAndProcess(){
    daoClass = new ClassB();
    callToDAOClassToDoThings(); //populates array lists among other things

    thisMethodCausesTheTrouble(getAList().size);


    public void classToDAOClassToDoThings(){
    daoClass.populateListsAndProcess()
    setterForAList(daoClass.getThatList())
    }

   public void thisMethodCausesTheTrouble(int size){
      if(size < 1){
      do something
      return 0;
      }else{
       do something else
       return 1;
      }
   }
    }
}

I have broken my code up and separated as much as I can, but I cannot seem to kill the mutations that arise from these if/else statements.. I have tried this test and several variations but it does not work - The test passes, but the mutation survives:

@Test
public void thisMethodCausesTheTroubleTest() throws Exception {
    classUnderTest = PowerMockito.mock(SendExceptionTickets.class);
    PowerMockito.mockStatic(AmazonSimpleEmailServiceClientBuilder.class);
    AmazonSimpleEmailServiceClientBuilder yep = PowerMockito.mock(AmazonSimpleEmailServiceClientBuilder.class);
    PowerMockito.when(yep.standard()).thenReturn(yep);
    PowerMockito.when(yep.withRegion(any(Regions.class))).thenReturn(yep);
    PowerMockito.when(yep.build()).thenReturn(emailServiceMock);
    PowerMockito.when(emailServiceMock.sendEmail(request)).thenReturn(result);

    assertEquals(0, classUnderTest.sendEmailOrNot(0));
}

I have other conditionals that I have to deal with as well so I'm hoping for a little guidance to get me going.