Using T4 to make redundant code more maintainable

#1 - Exceptions.tt

<#@ template language="C#" #>
<#@ output extension=".cs" #>
<#
var exceptions = new []
{
	DefineException("Message"),
	DefineException("BadResponse").DerivedFrom("Message"),
	DefineException("InvalidState")
};
//----------------------------------------------------------------------------------
#>
using System;
using System.Runtime.Serialization;

namespace MyNamespace
{
<# foreach(var exception in exceptions) { #>
	[Serializable]
	public partial class <#= exception.ClassName #> : <#= exception.BaseClassName #>
	{
		public <#= exception.ClassName #> () : base () {}
		public <#= exception.ClassName #> (string message) : base (message) {}
		public <#= exception.ClassName #> (string message, Exception inner) : base (message, inner) {}
		protected <#= exception.ClassName #> (SerializationInfo info, StreamingContext context) : base (info, context) {}
	}

<# } #>
}
<#+ 
//----------------------------------------------------------------------------------
ExceptionDefinition DefineException(string name)
{
	return new ExceptionDefinition { Name = name, BaseName = "" };
}

class ExceptionDefinition
{
	public string Name;
	public string BaseName;

	public string ClassName { get { return Name + "Exception"; } }
	public string BaseClassName { get { return BaseName + "Exception"; } }

	public ExceptionDefinition DerivedFrom(string baseName) { BaseName = baseName; return this; }
}
#>

#2 - Exceptions.cs

using System;
using System.Runtime.Serialization;

namespace MyNamespace
{
	[Serializable]
	public partial class MessageException : Exception
	{
		public MessageException () : base () {}
		public MessageException (string message) : base (message) {}
		public MessageException (string message, Exception inner) : base (message, inner) {}
		protected MessageException (SerializationInfo info, StreamingContext context) : base (info, context) {}
	}

	[Serializable]
	public partial class BadResponseException : MessageException
	{
		public BadResponseException () : base () {}
		public BadResponseException (string message) : base (message) {}
		public BadResponseException (string message, Exception inner) : base (message, inner) {}
		protected BadResponseException (SerializationInfo info, StreamingContext context) : base (info, context) {}
	}

	[Serializable]
	public partial class InvalidStateException : Exception
	{
		public InvalidStateException () : base () {}
		public InvalidStateException (string message) : base (message) {}
		public InvalidStateException (string message, Exception inner) : base (message, inner) {}
		protected InvalidStateException (SerializationInfo info, StreamingContext context) : base (info, context) {}
	}

}

#3 - ExceptionExtensions.cs

namespace MyNamespace
{
	public partial class InvalidStateException
	{
		public int StatusCode { get; set; }
	}
}