### Question:
DefaultTemporalGeometricPrimitive extends DefaultTemporalPrimitive implements TemporalGeometricPrimitive, Separation { @Override public Duration length() { Duration response = null; long diff = 0L; if (this instanceof Instant) { response = new DefaultPeriodDuration(Math.abs(diff)); return response; } else { if (this instanceof Period) { if (((Period) this).getBeginning() != null && ((Period) this).getEnding() != null) { response = ((DefaultInstant) ((Period) this).getBeginning()).distance(((DefaultInstant) ((Period) this).getEnding())); return response; } } return null; } } DefaultTemporalGeometricPrimitive(Map<String, ?> properties); protected  DefaultTemporalGeometricPrimitive(); protected  DefaultTemporalGeometricPrimitive(final TemporalGeometricPrimitive object); @Override Duration distance(final TemporalGeometricPrimitive other); @Override Duration length();  }### Answer:
@Test public void testLength() { }