public static async Task <string> CreateSignedJwtAsync(
object header, object payload, ISigner signer,
CancellationToken cancellationToken = default(CancellationToken))
{
string encodedHeader = Encode(header);
string encodedPayload = Encode(payload);
var assertion = new StringBuilder();
assertion
.Append(Encode(header))
.Append('.')
.Append(Encode(payload));
var bytesToSign = Encoding.UTF8.GetBytes(assertion.ToString());
var signature = await signer.SignDataAsync(bytesToSign, cancellationToken)
.ConfigureAwait(false);
assertion.Append('.').Append(UrlSafeBase64Encode(signature));
return(assertion.ToString());
}