### Question:
PlaintextMessageRenderer implements FXMessageRenderer { @Override public String renderString(String dropPayload, ResourceBundle resourceBundle) { return TextMessage.fromJson(dropPayload).getText(); } PlaintextMessageRenderer(); @Override TextFlow render(String prefixAlias, String dropPayload, ResourceBundle resourceBundle); @Override String renderString(String dropPayload, ResourceBundle resourceBundle); HyperlinkRenderer getHyperlinkRenderer();  }### Answer:
@Test public void rendersPlaintextFromJson() { String message = renderer.renderString(payload, null); assertEquals("content", message); }