### Question:
urn_perun_group_attribute_def_def_collectionID extends GroupAttributesModuleAbstract implements GroupAttributesModuleImplApi { @Override public void checkAttributeSemantics(PerunSessionImpl sess, Group group, Attribute attribute) throws WrongReferenceAttributeValueException { if (attribute.getValue() == null) throw new WrongReferenceAttributeValueException(attribute, "Attribute collectionID cannot be null."); }  @Override void checkAttributeSemantics(PerunSessionImpl sess, Group group, Attribute attribute); @Override AttributeDefinition getAttributeDefinition();  }### Answer:
@Test(expected = WrongReferenceAttributeValueException.class) public void testCheckNullValue() throws Exception { System.out.println("testCheckNullValue()"); attributeToCheck.setValue(null); classInstance.checkAttributeSemantics(sess, group, attributeToCheck); }
@Test public void testCorrectSemantics() throws Exception { System.out.println("testCorrectSyntax()"); attributeToCheck.setValue("0"); classInstance.checkAttributeSemantics(sess, group, attributeToCheck); }