Function foreachkey

src/master/master.cpp:1167–1171

    allocator->removeSlave(slave->id);

    foreachkey (const FrameworkID& frameworkId, utils::copy(slave->tasks)) {
      foreachvalue (Task* task, utils::copy(slave->tasks[frameworkId])) {
        removeTask(task);
      }
    }

    // Remove executors.
    foreachkey (const FrameworkID& frameworkId, utils::copy(slave->executors)) {