### Question:
AssociationPropertyReader extends BasePropertyReader implements EdgePropertyReader { @Override public String getSourceId() { return association.getSourceRef().getId(); } AssociationPropertyReader(Association association,
                                     BPMNDiagram diagram,
                                     DefinitionResolver definitionResolver); @Override String getSourceId(); @Override String getTargetId(); Class getAssociationByDirection(); @Override Connection getSourceConnection(); @Override Connection getTargetConnection(); @Override List<Point2D> getControlPoints(); @Override DefinitionResolver getDefinitionResolver();  }### Answer:
@Test public void testGetSourceId() { assertEquals(SOURCE_ID, propertyReader.getSourceId()); }