Sigv4.pair: def of bend-kit-sigv4@0.11.0.1
Import: import bend-kit-sigv4@0.11.0.1/sigv4.bend as Sigv4
Lines 136-142 of bend-kit-sigv4@0.11.0.1/sigv4.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-sigv4@0.11.0.1/sigv4.bend&start_line=136&end_line=142

import Base

# Canonical query: split on '&', each "k=v" (a bare "k" is "k="), re-encoded, sorted by key then value.
def pair(xs: List<&2, String>) -> Sigma<&2, &2, String, _ => String>:
  match xs:
    case Nil{}:
      ("", "")
    case Con{k, t}:
      (norm(k), norm(String.join(t, "=")))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.join
  https://jend.leeeet.dev/definition.txt?path=bend-kit-sigv4@0.11.0.1/sigv4.bend&name=norm