4 * perf: improve header token parsing speed
9 * perf: hoist regular expression
14 * Only accept valid field names in the `field` argument
15 - Ensures the resulting string is a valid HTTP header value
20 * Fix setting empty header from empty `field`
21 * perf: enable strict mode
22 * perf: remove argument reassignments
27 * Accept valid `Vary` header string as `field`
28 * Add `vary.append` for low-level string manipulation
29 * Move to `jshttp` orgainzation
34 * Support array of fields to set