def lines.append
import gralha-coverage@0.1.0.1/cover.bend as Coverimport Base
168def lines.append(xs: List<&2, CovLine>, ys: List<&2, CovLine>) -> List<&2, CovLine>:
169 match xs:
170 case Nil{}: ys
171 case Con{h, t}: Con{h, lines.append(t, ys)}