def from_serializable(serializable)
      super(serializable)
      @proposer = nil
      unless serializable['user1'].nil?
        @proposer = User.new
        @proposer.from_serializable(serializable['user1'])
      end
      @proposed = nil
      unless serializable['user2'].nil?
        @proposed = User.new
        @proposed.from_serializable(serializable['user2'])
      end
      @subscriptions = []
      unless serializable['subscriptions'].nil?
        @subscriptions = serializable['subscriptions'].map do
        |subscription_serializable|
          subscription = Subscription.new
          subscription.from_serializable(subscription_serializable)
          subscription
        end
      end
      @confirmed_by_proposer = serializable['userconfirmed1']
      @confirmed_by_proposed = serializable['userconfirmed2']
      @privacy_level = serializable['publicvisible']
    end
def from_serializable(serializable)
      super(serializable)
      @proposer = nil
      unless serializable['user1'].nil?
        @proposer = User.new
        @proposer.from_serializable(serializable['user1'])
      end
      @proposed = nil
      unless serializable['user2'].nil?
        @proposed = User.new
        @proposed.from_serializable(serializable['user2'])
      end
      @subscriptions = []
      unless serializable['subscriptions'].nil?
        @subscriptions = serializable['subscriptions'].map do
        |subscription_serializable|
          subscription = Subscription.new
          subscription.from_serializable(subscription_serializable)
          subscription
        end
      end
      @confirmed_by_proposer = serializable['userconfirmed1']
      @confirmed_by_proposed = serializable['userconfirmed2']
      @privacy_level = serializable['publicvisible']
    end
:category: Serialization

 Creates itself from a serializable representation, which only contains
 simple data types.
 serializable:: A hash with the keys:
 * uri:: The URI.
 * id:: The identifier.
 * user1:: A User serializable of the proposer.
 * user2:: A User serializable of the proposed.
 * subscriptions:: Subscription serializables.
 * userconfirmed1:: True if the proposing User has confirmed it, false otherwise.
 * userconfirmed2:: True if the proposed User has confirmed it, false otherwise.
 * publicvisible:: The privacy level, see PrivacyLevel constants.