List<Expression> values = Lists.newArrayList();
values.add(new StringConstant(attr, elementSchema," " + attr.getName()));
values.add(new Conditional(
attr, elementSchema,
new IsXmlExpression(attr, elementSchema),
new StringConstant(attr, elementSchema,
"=\"" + attr.getName() + "\""),
new StringConstant(attr, elementSchema, "")));
return Concatenation.create(attr.getSourcePosition(), elementSchema, values);