boolean oldSerializeNulls = writer.getSerializeNulls();
writer.setSerializeNulls(serializeNulls);
try {
((TypeAdapter<Object>) adapter).write(writer, src);
} catch (IOException e) {
throw new JsonIOException(e);
} finally {
writer.setLenient(oldLenient);
writer.setHtmlSafe(oldHtmlSafe);
writer.setSerializeNulls(oldSerializeNulls);
}