fn meet_assign(&mut self, other: &Self) where Self: Sized  {
        *self = self.meet(other);
    }
Updates `self` to the largest element less than or equal to both arguments.

# Examples

```
# use timely::PartialOrder;
# use timely::order::Product;
# use differential_dataflow::lattice::Lattice;
# fn main() {

let mut time1 = Product::new(3, 7);
let time2 = Product::new(4, 6);
time1.meet_assign(&time2);

assert_eq!(time1, Product::new(3, 6));
# }
```
differential-dataflow/src/lattice.rs