class ReeObject::DumpAsJson

def convert_object(obj, cache)
  if cache.key?(obj.object_id)
    raise RecursiveObjectErr, "Recursive object found: #{obj}"
  end
  cache[obj.object_id] = true
  result = []
  obj.instance_variables.each do |var|
    result << [
      recursively_convert(var, cache),
      recursively_convert(obj.instance_variable_get(var), cache),
    ]
  end
  result
end