### Question:
ObjectNoOpFilter implements ObjectFilter { @Override public List<DescribeSObjectResult> filter(List<DescribeSObjectResult> dsrs) { return dsrs; }  @Override List<DescribeSObjectResult> filter(List<DescribeSObjectResult> dsrs);  }### Answer:
@Test public void testFilterWithNullValue() { assertNull(new ObjectNoOpFilter().filter(null), "A no op filter of a null value should be null"); }
@Test public void testFilterWithNonNullValue() { DescribeSObjectResult dsr = new DescribeSObjectResult(); dsr.setName("Object_Name__c"); List<DescribeSObjectResult> dsrs = new ObjectNoOpFilter().filter(Collections.<DescribeSObjectResult>singletonList(dsr)); assertNotNull(dsrs, "A no op filter of a non-null value should be non-null"); assertEquals(dsrs.size(), 1, "Unexpected number of DescribeSObjectResults after no op filter"); assertEquals(dsrs.get(0).getName(), "Object_Name__c", "Unexpected DescribeSObjectResult after no op filter"); }