pub fn merge<I, J>(
    i: I,
    j: J
) -> Merge<<I as IntoIterator>::IntoIter, <J as IntoIterator>::IntoIter>where
    I: IntoIterator,
    J: IntoIterator<Item = I::Item>,
    I::Item: PartialOrd,Expand description
Create an iterator that merges elements in i and j.
IntoIterator enabled version of i.merge(j).
use itertools::merge;
for elt in merge(&[1, 2, 3], &[2, 3, 4]) {
    /* loop body */
}