JS Object representation of a stack frame

Check if a URL is absolute

Unpack a browser type and version from the useragent string

Eliminates layout thrashing by batching DOM read/write operations

hashmap + constructor function = a hashmap you don't have to check before calling get()

Efficiently use an Observer (i.e. IntersectionObserver) without the ugly observer callback. `insular-observer` gives you a simple, per-target `observe/unobserve` API that uses the same observer instance internally.