/// <summary>
/// Creates a signature for the specified text
/// but does not embed it into the text.
/// </summary>
/// <param name="signer">The <see cref="ISigner"/>
/// instance that is used to generate the signature.</param>
/// <param name="text">The text for which to generate a signature.</param>
/// <param name="privateKey">The private key for signing the text.</param>
/// <returns>The signature block, which can be placed alongside
/// or within the text.</returns>
/// <exception cref="ArgumentNullException">
/// Occurs if any of the arguments are null.</exception>
public async Task <string> CreateButDoNotEmbedSignatureAsync(
ISigner signer, string text, string privateKey)
{
AssertArg.IsNotNull(signer, nameof(signer));
AssertArg.IsNotNull(text, nameof(text));
AssertArg.IsNotNull(privateKey, nameof(privateKey));
string signatureText = await signer.CreateBase64SignatureAsync(text, privateKey, Encoding);
string result = $"<![CDATA[{SignatureIndicator}{signatureText}]]>";
return(result);
}
