def to_hash
      hash = {}
      members.each do |key|
        value = send(key)
        hash[key.to_sym] = value unless value.nil?
      end
      hash
    end
def to_hash
      hash = {}
      members.each do |key|
        value = send(key)
        hash[key.to_sym] = value unless value.nil?
      end
      hash
    end
Public