### Question:
LauncherConfiguration implements LauncherOptions { public JsonElement toJson() { return new GsonBuilder().serializeNulls().disableHtmlEscaping().create().toJsonTree(this); }  boolean isFileDownloadCleanupOnInvocation(); T setFileDownloadCleanupOnInvocation(boolean val); boolean isFileDownloadCheckTimeStampOnInvocation(); T setFileDownloadCheckTimeStampOnInvocation(boolean val); String getSeLionConfig(); T setSeLionConfig(String config); void merge(LauncherOptions other); @Override String toString(); JsonElement toJson(); LauncherConfiguration fromJson(JsonElement json); LauncherConfiguration fromJson(String json); static LauncherConfiguration loadFromFile(String configFile); static final String SELION_CONFIG; static final String SELION_CONFIG_ARG; static final String DOWNLOAD_CLEANUP; static final String DOWNLOAD_CLEANUP_ARG; static final String DOWNLOAD_TIMESTAMP_CHECK; static final String DOWNLOAD_TIMESTAMP_CHECK_ARG; }### Answer:
@Test public void testToJson() { LauncherConfiguration lc = new LauncherConfiguration(); lc.setFileDownloadCheckTimeStampOnInvocation(false); JsonElement json = lc.toJson(); assertNotNull(json); assertFalse(json.getAsJsonObject().get("downloadTimeStampCheck").getAsBoolean()); assertTrue(json.getAsJsonObject().get("downloadCleanup").getAsBoolean()); assertFalse(json.getAsJsonObject().has("selionConfig")); }