les to a DDSketch and invoke the `quantile` method to pull any quantile from
*0.0* to *1.0*.

```rust
use sketches_ddsketch::{Config, DDSketch};

let c = Config::defaults();
let mut d = DDSketch::new(c);

d.add(1.0);
d.add(1.0);
d.add(1.0);

let q = d.quantile(0.50).unwrap();

assert!(q < Some(1.01));
assert!(q > Some(0.99));
```

Sketches can also be merged.

```rust
use sketches_ddsketch::{Config, DDSketch};

let c = Config::defaults();
let mut d1 = DDSketch::new(c);
let mut d2 = DDSketch::new(c);

d1.add(1.0);
d2.add(2.0);
d2.add(2.0);

d1.merge(&d2);

assert_eq!(d1.count(), 3);
```