/// <summary>
/// Retrieves, as an XName in an option, the namespace name in this namespace resolver corresponding to the specified prefix, paired with the local name.
/// If the prefix is unknown, the option will be empty.
/// </summary>
/// <param name="namespaceResolver"></param>
/// <param name="prefix"></param>
/// <param name="localName"></param>
/// <returns></returns>
public static Opt <XName> GetXNameOpt(this IXmlNamespaceResolver namespaceResolver, string prefix, string localName)
{
if (namespaceResolver == null)
{
throw new ArgumentNullException("namespaceResolver");
}
if (prefix == null)
{
throw new ArgumentNullException("prefix");
}
if (localName == null)
{
throw new ArgumentNullException("localName");
}
return(namespaceResolver.GetXNamespaceOpt(prefix).SelectFix(xns => xns.GetName(localName)));
}
