gistfile1.rb

 def check_classes
   # Get list of all subclasses of Scanny::Checks::Check.
   classes = []
   ObjectSpace.each_object(Class) do |klass|
     classes << klass if klass < Scanny::Checks::Check
   end

   # Filter out classes that are a superclass of some other class in the list.
   # This way only "leaf" classes remain.
   classes.reject do |klass|
     classes.any? { |c| c < klass }
   end

   classes.map(&:new)
 end