method FlattenedSign.prototype.setProtectedHeaderimport { FlattenedSign } from "https://dotland.deno.dev/x/jose@v5.9.2/index.ts"; setProtectedHeader(protectedHeader: JWSHeaderParameters): thisSets the JWS Protected Header on the FlattenedSign object. ParametersprotectedHeader: JWSHeaderParametersJWS Protected Header. Returnsthis