pub fn with_capacity(capacity: usize) -> BinaryHeap<T> {
        BinaryHeap { data: Vec::with_capacity(capacity) }
    }
Pushes an item onto the binary heap.

# Examples

Basic usage:

```
use std::collections::BinaryHeap;
let mut heap = BinaryHeap::new();
heap.push(3);
heap.push(5);
heap.push(1);

assert_eq!(heap.len(), 3);
assert_eq!(heap.peek(), Some(&5));
```

# Time complexity

The expected cost of `push`, averaged over every possible ordering of
the elements being pushed, and over a sufficiently large number of
pushes, is *O*(1). This is the most meaningful cost metric when pushing
elements that are *not* already in any sorted pattern.

The time c
benchmarks/haystacks/code/rust-library.rs