File list (Check if you may need any files):
Estrella_designPattern\DesignPatterns
......................\..............\DesignPatterns.sln
......................\..............\DesignPatterns.suo
......................\..............\DesignPatterns
......................\..............\..............\Billy.cs
......................\..............\..............\Billy.Designer.cs
......................\..............\..............\Billy.resx
......................\..............\..............\bin
......................\..............\..............\...\Debug
......................\..............\..............\...\.....\DesignPatterns.exe
......................\..............\..............\...\.....\DesignPatterns.pdb
......................\..............\..............\...\.....\DesignPatterns.vshost.exe
......................\..............\..............\...\.....\DesignPatterns.vshost.exe.manifest
......................\..............\..............\...\Release
......................\..............\..............\frmDesignPatterns.cs
......................\..............\..............\frmDesignPatterns.Designer.cs
......................\..............\..............\frmDesignPatterns.resx
......................\..............\..............\IObserver.cs
......................\..............\..............\ISubject.cs
......................\..............\..............\Jean.cs
......................\..............\..............\Jean.Designer.cs
......................\..............\..............\Jean.resx
......................\..............\..............\obj
......................\..............\..............\...\x86
......................\..............\..............\...\...\Debug
......................\..............\..............\...\...\.....\DesignPatterns.Billy.resources
......................\..............\..............\...\...\.....\DesignPatterns.csproj.FileListAbsolute.txt
......................\..............\..............\...\...\.....\DesignPatterns.csproj.GenerateResource.Cache
......................\..............\..............\...\...\.....\DesignPatterns.exe
......................\..............\..............\...\...\.....\DesignPatterns.frmDesignPatterns.resources
......................\..............\..............\...\...\.....\DesignPatterns.Jean.resources
......................\..............\..............\...\...\.....\DesignPatterns.pdb
......................\..............\..............\...\...\.....\DesignPatterns.Properties.Resources.resources
......................\..............\..............\...\...\.....\DesignTimeResolveAssemblyReferences.cache
......................\..............\..............\...\...\.....\DesignTimeResolveAssemblyReferencesInput.cache
......................\..............\..............\...\...\.....\Observer.csproj.FileListAbsolute.txt
......................\..............\..............\...\...\.....\Observer.csproj.GenerateResource.Cache
......................\..............\..............\...\...\.....\Observer.csprojResolveAssemblyReference.cache
......................\..............\..............\...\...\.....\TempPE
......................\..............\..............\Observer.cs
......................\..............\..............\Observer.csproj
......................\..............\..............\Program.cs
......................\..............\..............\Properties
......................\..............\..............\..........\AssemblyInfo.cs
......................\..............\..............\..........\Resources.Designer.cs
......................\..............\..............\..........\Resources.resx
......................\..............\..............\..........\Settings.Designer.cs
......................\..............\..............\..........\Settings.settings
......................\..............\..............\Subject.cs