exceptionHandler.sourceLine, exceptionHandler.sourceColumn);
else if (argsSize != 1) {
addError("Exception handler must take exactly 1 argument (this one takes "
+ argsSize + ")", exceptionHandler.sourceLine, exceptionHandler.sourceColumn);
} else {
for (Node child : exceptionHandler.children()) {
PatternRule rule = (PatternRule) child;
// Should have only 1 arg pattern.
Node patternNode = rule.patterns.get(0);
if (patternNode instanceof PrivateField) {