var processor = new HashtagProcessor();
string post1 = "Learning modern C# is #fun and #rewarding today!";
string post2 = "Just a normal post without any tags.";
string post3 = "#coding #csharp #dotnet are my favorite topics.";
string post4 = "   ";
string post5 = "The event is #Awesome!";
Console.WriteLine($"Post 1 Tags: {processor.ExtractTags(post1)}");
Console.WriteLine($"Post 2 Tags: {processor.ExtractTags(post2)}");
Console.WriteLine($"Post 3 Tags: {processor.ExtractTags(post3)}");
Console.WriteLine($"Post 4 Tags: {processor.ExtractTags(post4)}");
Console.WriteLine($"Post 5 Tags: {processor.ExtractTags(post5)}");