Map<AttributeName, PositionalNodeType> variables = varCollector.getAttributes();
for (AttributeName variable : declaredVariables) {
NodeType type = variables.get(variable);
if (type == null) {
String literal = variable.getLiteral();
throw new ParserException(new TIdentifier(literal), "Failed to find variable " +
literal + " in where clause. ");
} else {
Attribute attribute = new AttributeImpl(variable, type);
newAttributes.add(attribute);
}