### Question:
GatewayPropertyWriter extends PropertyWriter { public void setDefaultRoute(String defaultRouteExpression) { if (defaultRouteExpression == null) { return; } CustomAttribute.dg.of(gateway).set(defaultRouteExpression); String[] split = defaultRouteExpression.split(" : "); this.defaultGatewayId = (split.length == 1) ? split[0] : split[1]; } GatewayPropertyWriter(Gateway gateway, VariableScope variableScope); void setDefaultRoute(String defaultRouteExpression); void setSource(BasePropertyWriter source); void setTarget(BasePropertyWriter target); void setGatewayDirection(Node n); void setGatewayDirection(GatewayDirection direction);  }### Answer:
@Test public void testSetDefaultRoute() { testSetDefaultRoute("defaultRoute", "defaultRoute"); }
@Test public void testSetDefaultRouteNull() { propertyWriter.setDefaultRoute(null); verify(featureMap, never()).add(any()); }