siOptional

siOptional is a utility class that provides a way to represent a value that may or may not be present. It is similar to the `Optional` class found in Java or C++'s `std::optional`. The primary purpose of siOptional is to help avoid null pointer exceptions by forcing developers to explicitly handle the case where a value might be absent.

An siOptional object can either contain a value or be empty. It is created using static factory methods such as `siOptional.of(value)` to create an siOptional containing a value, or `siOptional.empty()` to create an empty siOptional. Methods like `isPresent()` can be used to check if a value is contained within the siOptional. If a value is present, `get()` can be used to retrieve it. However, calling `get()` on an empty siOptional will result in an error, which is precisely what the class aims to prevent by encouraging explicit checks.

siOptional also offers methods for functional programming paradigms. `orElse(defaultValue)` returns the contained value if present, otherwise it returns a specified default value. `orElseThrow(exceptionSupplier)` returns the contained value if present, otherwise it throws an exception supplied by a given supplier. These methods allow for more concise and safer handling of potentially absent values compared to traditional null checks. By using siOptional, code becomes more readable and less prone to runtime errors related to null references.