def inheritance_tree(include_mods = false)
      return [self] unless include_mods
      [self] + mixins(:instance, :class).map do |m|
        next if m == self
        next m unless m.respond_to?(:inheritance_tree)
        m.inheritance_tree(true)
      end.compact.flatten.uniq
    end
def inheritance_tree(include_mods = false)
      return [self] unless include_mods
      [self] + mixins(:instance, :class).map do |m|
        next if m == self
        next m unless m.respond_to?(:inheritance_tree)
        m.inheritance_tree(true)
      end.compact.flatten.uniq
    end
Returns the inheritance tree of mixins.

 @param [Boolean] include_mods if true, will include mixed in
   modules (which is likely what is wanted).
 @return [Array<NamespaceObject>] a list of namespace objects