in TeamCity.ServiceMessages/Write/ServiceMessageFormatter.cs [24:30]
public string FormatMessage([NotNull] string messageName, [NotNull] string singleValue)
{
if (string.IsNullOrEmpty(messageName)) throw new ArgumentNullException(nameof(messageName));
if (singleValue == null) throw new ArgumentNullException(nameof(singleValue));
if (ServiceMessageReplacements.Encode(messageName) != messageName) throw new ArgumentException("The message name contains illegal characters.", nameof(messageName));
return string.Format("{2}{0} '{1}'{3}", messageName, ServiceMessageReplacements.Encode(singleValue), ServiceMessageConstants.ServiceMessageOpen, ServiceMessageConstants.ServiceMessageClose);
}