### Question:
XDateRangeConverter implements XRangeConverter { @Override public boolean isApplicable(Class<? extends XRange> clazz) { Preconditions.checkNotNull(clazz); return XDateRange.class.isAssignableFrom(clazz); }  @Override boolean isApplicable(Class<? extends XRange> clazz); @Override String convertStart(XRange xRange); @Override String convertEnd(XRange xRange); @Override String convertGap(XRange xRange);  }### Answer:
@Test public void isApplicable() { assertTrue(xDateRangeConverter.isApplicable(XDateRange.class)); assertFalse(xDateRangeConverter.isApplicable(XRange.class)); }
@Test(expected = NullPointerException.class) public void isApplicable_NULL_CLASS_ARGUMENT() { xDateRangeConverter.isApplicable(null); }