@Test
public void fillAttribute() throws Exception {

	System.out.println("fillAttribute()");
	Attribute attribute = classInstance.fillAttribute(session, group, resource, classInstance.getAttributeDefinition());
	Object attributeValue = attribute.getValue();
	assertThat(attributeValue, is(notNullValue()));
	List<String> expectedValue = new ArrayList<>();
	expectedValue.add(adName + "@group.muni.cz");
	assertThat(attributeValue, equalTo(expectedValue));
	//check that value generated by fillAttribute() is acceptable for checkAttributeSemantics()
	when(am.getPerunBeanIdsForUniqueAttributeValue(eq(session), argThat(new BeanAttributeMatcher("group_resource"))))
			.thenReturn(Sets.newHashSet(new Pair<>(group.getId(),resource.getId())));
	when(am.getPerunBeanIdsForUniqueAttributeValue(eq(session), argThat(new BeanAttributeMatcher("member"))))
			.thenReturn(Sets.newHashSet());
	classInstance.checkAttributeSemantics(session, group, resource, attribute);
}