def pairs
import bend-kit-sigv4@0.11.0.1/sigv4.bend as Sigv4import Base
151def pairs(xs: List<&2, String>) -> List<&2, Sigma<&2, &2, String, _ => String>>:
152 match xs:
153 case Nil{}:
154 Nil{}
155 case Con{+h, t}:
156 pairs.if(String.is_empty(h), h, pairs(t))