pub fn consolidate(&self) -> Self {
        use crate::trace::implementations::{KeyBatcher, KeyBuilder, KeySpine};
        self.consolidate_named::<KeyBatcher<_, _, _>,KeyBuilder<_,_,_>, KeySpine<_,_,_>>("Consolidate")
    }
Aggregates the weights of equal records into at most one record.

This method uses the type `D`'s `hashed()` method to partition the data. The data are
accumulated in place, each held back until their timestamp has completed.

# Examples

```
use differential_dataflow::input::Input;

::timely::example(|scope| {

let x = scope.new_collection_from(1 .. 10u32).1;

x.negate()
.concat(&x)
.consolidate() // <-- ensures cancellation occurs
.assert_empty();
});
```
differential-dataflow/src/operators/consolidate.rs