Ruby Hash#has_keys?

gistfile1.rb

class Hash
  def has_keys?(*keys)
    keys.inject(self) do |pointer, key|
      return false if !pointer.respond_to?(:has_key?) || !pointer.has_key?(key)
      pointer[key]
    end
    true
  end
end

h = {:one => {:two => :three}}
p h.has_keys?(:one, :two)