@Test
  public void testItSetsDayColumns() {
    // simulate Feb month
    when(calendar.get(Calendar.DAY_OF_WEEK)).thenReturn(1);
    when(calendar.get(Calendar.MONTH)).thenReturn(1);
    when(calendar.getActualMaximum(Calendar.DAY_OF_MONTH)).thenReturn(28);

    String[] dayNames = {"Mon", "Tue", "Wed", "Thur", "Fri", "Sat", "Sun"};
    underTest.setGrowProgress(
        1000); // set grow progress so that it simulates the calendar being open
    underTest.setDayColumnNames(dayNames);
    underTest.drawMonth(canvas, calendar, 0);

    InOrder inOrder = inOrder(canvas);
    inOrder.verify(canvas).drawText(eq("Mon"), anyInt(), anyInt(), eq(paint));
    inOrder.verify(canvas).drawText(eq("Tue"), anyInt(), anyInt(), eq(paint));
    inOrder.verify(canvas).drawText(eq("Wed"), anyInt(), anyInt(), eq(paint));
    inOrder.verify(canvas).drawText(eq("Thur"), anyInt(), anyInt(), eq(paint));
    inOrder.verify(canvas).drawText(eq("Fri"), anyInt(), anyInt(), eq(paint));
    inOrder.verify(canvas).drawText(eq("Sat"), anyInt(), anyInt(), eq(paint));
    inOrder.verify(canvas).drawText(eq("Sun"), anyInt(), anyInt(), eq(paint));
  }
 @Test(expected = IllegalArgumentException.class)
 public void testItThrowsWhenDayColumnsIsNotLengthSeven() {
   String[] dayNames = {"Mon", "Tue", "Wed", "Thur", "Fri"};
   underTest.setDayColumnNames(dayNames);
 }