ruby - Module method access restriction -

i have class c inherits class a , includes module b. a has method baz.

class   def baz; 5 end end  module b   def foobaz; baz end end  class c <   include b   def barbaz; baz end end 

i want disallow b instance (indirectly) calling baz, allow c instance call baz.

b.new.foobaz # => error c.new.foobaz # => no error c.new.barbaz # => no error 

how this?

maybe wanted ?

class   def baz; 5 end end  module b   module_function   def foobaz     self.respond_to(:baz) ? baz : "no baz defined :("   end end  class c <   include b   def barbaz; baz end end  b.foobaz # => "no baz defined :(" c.new.foobaz # => 5 c.new.barbaz # => 5