def fed=(fed)
      obj = ICU::Federation.find(fed)
      @fed = obj ? obj.code : nil
      raise "invalid tournament federation (#{fed})" if @fed.nil? && fed.to_s.strip.length > 0
    end
def fed=(fed)
      obj = ICU::Federation.find(fed)
      @fed = obj ? obj.code : nil
      raise "invalid tournament federation (#{fed})" if @fed.nil? && fed.to_s.strip.length > 0
    end
Constructor. Name and start date must be supplied. Other attributes are optional.
 Set the tournament federation. Can be _nil_.