{
final TernaryChoiceOperator operator =
new TernaryChoiceOperator(_diagnosticFactory);
final Diagnostic diagnostic =
operator.validate(choiceArg/* whenTrueArg, whenFalseArg*/);
if (diagnostic.getSeverity() != Diagnostic.OK)
{
final Token firstToken = node.getFirstToken();
final int offset = _context.getDocumentPosition() + firstToken.beginColumn - 1;