public static <T> ToByteOrElseGet<T>
    byteOrElseGet(ToByteNullable<T> expression, ToByte<T> defaultGetter) {
        return new ToByteOrElseGetImpl<>(expression, defaultGetter);
    }
Returns an expression that returns the same value as the specified
expression if it is not {@code null}, and if the wrapped expression
returns {@code null}, applies a different expression to the input.

@param expression     the nullable expression to wrap
@param defaultGetter  getter for the default value from the input
@param <T>            the input entity type
@return               the non-nullable expression
runtime-parent/runtime-compute/src/main/java/com/speedment/runtime/compute/internal/expression/OrElseGetUtil.java