How to use the app-builder-lib/out/codeSign/macCodeSign.isSignAllowed function in app-builder-lib

private async signDmg(artifactPath: string) {
    if (!isSignAllowed(false)) {
      return
    }

    const packager = this.packager
    const qualifier = packager.platformSpecificBuildOptions.identity
    // explicitly disabled if set to null
    if (qualifier === null) {
      // macPackager already somehow handle this situation, so, here just return
      return
    }

    const keychainFile = (await packager.codeSigningInfo.value).keychainFile
    const certificateType = "Developer ID Application"
    let identity = await findIdentity(certificateType, qualifier, keychainFile)
    if (identity == null) {
      identity = await findIdentity("Mac Developer", qualifier, keychainFile)