Как узнать исходный код метода из dll через код C#?

using ICSharpCode.Decompiler;
using ICSharpCode.Decompiler.Ast;
using Mono.Cecil;
using Mono.Cecil.Rocks;
...
private static string GetSourceCode(string typeName, string methodName)
{
    ModuleDefinition module = ModuleDefinition.ReadModule(@"c:\path\to\asm.dll");
    TypeDefinition type = module.Types.Single(t => t.FullName == typeName);
    MethodDefinition method = type.Methods.Single(t => t.Name == methodName);
    AstBuilder astBuilder = new AstBuilder(new ICSharpCode.Decompiler.DecompilerContext(type.Module) { CurrentType = type });
    astBuilder.AddMethod(method);
    using (var output = new StringWriter())
    {
        astBuilder.GenerateCode(new PlainTextOutput(output));
        return output.ToString();
    }
}