pageContext.setDevice(session.getDevice());
// Create an expression context for the environment context.
final ExpressionFactory factory = ExpressionFactory.getDefaultInstance();
final EnvironmentInteractionTracker simpleTracker =
new SimpleEnvironmentInteractionTracker();
final ExpressionContext exprContext = factory.
createExpressionContext(simpleTracker,
new DefaultNamespacePrefixTracker());
// Associate the expression context with the environment context.