#includeIn this example, two UtlString objects are created - `str1` and `str2`. The `isNull` function is then called on each of these objects to determine if they are null or empty. The first string `str1` is not null or empty, whereas the second string `str2` is null or empty. The package library for UtlString is likely part of a larger utility library or framework for C++.#include int main() { UtlString str1 = "hello"; UtlString str2; if (str1.isNull()) { std::cout << "String is null or empty" << std::endl; } else { std::cout << "String is not null or empty" << std::endl; } if (str2.isNull()) { std::cout << "String is null or empty" << std::endl; } else { std::cout << "String is not null or empty" << std::endl; } return 0; }