private string GetUsernameFromClaim(string claimsEncodedUsername)
{
    using (new SPMonitoredScope("GetUsernameFromClaim method start"))
    {
        try
        {
            SPClaimProviderManager spClaimProviderManager = SPClaimProviderManager.Local;
            if (spClaimProviderManager != null)
            {
                if (SPClaimProviderManager.IsEncodedClaim(claimsEncodedUsername))
                {
                    // return the normal domain/username without any claims identification data
                    return spClaimProviderManager.ConvertClaimToIdentifier(claimsEncodedUsername);
                }
            }
        }
        catch (Exception ex)
        {
            // You should handle any exceptions in here instead of ignoring them!
            // Logger.Log("An exception occured in the GetUsernameFromClaim() method");
            return claimsUsername; // Or just return the original username.
        }

        // Return the original username value if it couldn't be resolved as a claims username
        return claimsUsername;
    }
}