class Domaintree
    include Enumerable
    def initialize
           @doms = ["."]
           @leafs = []
        end

        def add(leaf)
                @leafs << leaf
        end

        def get(leaf)

        end

        def get
            @leafs
        end

        def end?
            true
        end

        def to_s
         puts @doms
        end


end

class Domain
    include Enumerable
         @domain
         @subdomains = []

        def initialize(par)
            puts par.class
            puts  @paren.class
            setparent(par)
            setdom(dom)
        end

        def setparent(parent)
            @parent  = parent
        end
        def  setdom(dom)
            @domain = dom
        end

        def getparent
            @parent
        end

        def  getdom
            @domain
        end

        def  addsub(dom)
            @subdomains <<self.new(dom,@parent)
        end

        def getsub(dom)
           @subdomains

        end

        def delsub(dom)

        end

end

irb(main):1790:0* test1 = Domaintree.new
.
=>
irb(main):1791:0> est2 = Domain.new(test1)
Domaintree
NilClass
NameError: .
undefined local variable or method `dom' for #<Domain:0x000000009bb630>
        from (irb):1756:in `initialize'
        from (irb):1791:in `new'
        from (irb):1791
        from /usr/bin/irb:12:in `<main>'
irb(main):1792:0>