class default extends Declarationimport { default } from "https://deno.land/x/postcss_autoprefixer@0.2.4/lib/hacks/flex.js"; Methodsnormalize()Return property name by final spec prefixed(prop, prefix)Change property name for 2009 spec set(decl, prefix)Spec 2009 supports only first argument Spec 2012 disallows unitless basis