if (!(e.getLHS() instanceof EntitySimpleProperty))
throw new NotImplementedException("Appengine only supports simple property expressions");
if (!(e.getRHS() instanceof LiteralExpression))
throw new NotImplementedException("Appengine only supports simple property expressions");
EntitySimpleProperty lhs = (EntitySimpleProperty) e.getLHS();
LiteralExpression rhs = (LiteralExpression) e.getRHS();
String propName = lhs.getPropertyName();
Object propValue = Expression.literalValue(rhs);
// Support for filtering navigation properties by key
if (propName.contains("/")) {
propName = propName.substring(0, propName.indexOf("/"));