FunctionType funType = declaredTypeAsJSType.getFunType();
if (funType == null) {
return null;
}
DeclaredFunctionType declType = funType.toDeclaredFunctionType();
if (declType == null) {
return null;
}
int numFormals = declNode.getChildAtIndex(1).getChildCount();
int reqArity = declType.getRequiredArity();