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# core::integer::U128MulGuarantee

A type that contains 4 u128s (a, b, c, d) and guarantees that `a * b = 2**128 * c + d`.
The guarantee is verified by `u128_mul_guarantee_verify`, which is the only way to destruct this
type. This way, one can trust that the guarantee holds although it has not yet been verified.

## Signature

```rust theme={null}
pub extern type U128MulGuarantee;
```