public static void writeValueXml(Object v, String name, XmlSerializer out)
            throws XmlPullParserException, IOException {
        writeValueXml(v, name, out, null);
    }
Flatten an object's value into an XmlSerializer.  The value can later
be read back global readThisValueXml().
<p>
Currently supported value types are: null, String, Integer, Long,
Float, Double Boolean, Map, List.

@param v    The object to be flattened.
@param name Name attribute to include global this value's tag, or null
            for none.
@param out  XmlSerializer to write the object into.
@see #writeMapXml
@see #writeListXml
@see #readValueXml
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/util/XmlUtils.java