Function normalize_vec 

pub fn normalize_vec<T: Endpoint>(
    intervals: impl Into<RangeCase<T>>,
) -> RangeVec<T>

Normalizes the vector of intervals and returns a vector that represents the same set of values, without redundancy.

No-ops quickly when intervals is known to be normalized at compile time.

This operation always operates in place (constant space) and takes constant time when intervals is known to be normalized at compile time.

Barring pre-normalised input, this operation takes linear time when the input is already normalised or otherwise sorted, and \(\mathcal{O}(n \log n)\) time in the input size (number of ranges) in the general case.