@Override
    public void writeExternal(ObjectOutput out) throws IOException {
        ExternalizableUtil.getInstance().writeStrings(out, identities);
        ExternalizableUtil.getInstance().writeStrings(out, features);
        ExternalizableUtil.getInstance().writeSafeUTF(out, verAttribute);
    }
Determines whether or not a given feature is included in these entity
capabilities.

@param feature the feature
@return true if feature is included, false if not
xmppserver/src/main/java/org/jivesoftware/openfire/entitycaps/EntityCapabilities.java