True if two or more elements of route are identical

Recursively merges maps. Stolen from https://dnaeon.github.io/recursively-merging-maps-in-clojure/

If this val is a number, return that number incremented by one; otherwise, return 1. TODO: should probably be in utils.

Construct a filter which, when applied to a list of maps, will pass those which match these targets, where each target is a tuple key value.

Returns true unless val is nil, false or an empty sequence. Otherwise always ‘false’; never any other value.

Return the value of this key k in this map m, or this dflt value if there is none.