code: public void useNamespace(SerializerContext serializerContext, String namespace)
  	{
  		if (namespace != null && namespace.length() > 0)
  		{
  			if (serializerContext.knownNamespaces == null)
  			{
  				serializerContext.knownNamespaces = new HashSet<String>(8);
  			}
  			serializerContext.knownNamespaces.add(namespace);
  		}
  	}
docs: Inform the serializer that the given namespace will be used. This allows the serializer to bind a prefix early.
  
  @param namespace
  The namespace that will be used.