def up_voted?(votable)
      is_votable?(votable)
      vote = get_vote(votable)
      return false if vote.nil?
      return true if vote.has_attribute?(:up_vote) && vote.up_vote
      false
    end
def up_voted?(votable)
      is_votable?(votable)
      vote = get_vote(votable)
      return false if vote.nil?
      return true if vote.has_attribute?(:up_vote) && vote.up_vote
      false
    end
Returns true if the voter up voted the "votable".