blah.rb

# This comes from GenericWebLibrary
class BaseComponent
end

# This comes from RestExtensionLibrary
class RestComponent < BaseComponent
end

# In a language with mixins you could do
class SomeFilterStuff
  def initialize(base_component)...

  def login_required...

  def method_missing(...)
    base_component.send(...
  end
end

SomeFilterStuff.new(BaseComponent.new)
SomeFilterStuff.new(RestComponent.new)

# not more verbose and you've replaced a static decoration with a dynamic decoration. which is always preferable, since you can change the order, add more decorations, etc. at runtime.