git clone https://github.com/jmou/yakatak.git
git clone git@github.com:jmou/yakatak.git
class AssertionError extends Error {}
export function assert(expr: unknown): asserts expr {
if (expr === false || expr == null) {
throw new AssertionError();
}
}
export function checked<T>(value: T): NonNullable<T> {
assert(value);
return value;
}