function HydrogenGenerator:onCreate()
    self.productivity = 50 -- litros por dia
    -- ...
    if g_seasons ~= nil then
        self.originalProductivity = self.productivity
        self.productivity = self.originalProductivity * 6 / g_seasons.environment.daysPerSeason
    end
end

function HydrogenGenerator:onCreate()
    self.productivity = 50 -- litros por dia
    -- ...
    if g_seasons ~= nil then
        self.originalProductivity = self.productivity
        self.productivity = self.originalProductivity * 6 / g_seasons.environment.daysInSeason
        g_messageCenter:subscribe(SeasonsMessageType.SEASON_LENGTH_CHANGED, self.onSeasonLengthChanged, self)
    end
end
function HydrogenGenerator:delete()
  g_messageCenter:unsubscribeAll()
end
function HydrogenGenerator:onSeasonLengthChanged()
    -- Aqui usamos a produtividade original!
    self.productivity = self.originalProductivity * 6 / g_seasons.environment.daysPerSeason
end

function HydrogenGenerator:setProductivity(productivity)
    self.productivity = productivity
    if g_seasons ~= nil then
        if self.originalProductivity == nil then
            self.originalProductivity = self.productivity
        end
        self.productivity = self.originalProductivity * 6 / g_seasons.environment.daysPerSeason
    end
end