Attempts to increments all the lessons of all the curriculums in this
        MetaCurriculum. Note that calling this method does not guarantee the
        lesson of a curriculum will increment. The lesson of a curriculum will
        only increment if the specified measure threshold defined in the
        curriculum has been reached and the minimum number of episodes in the
        lesson have been completed.

        Args:
            measure_vals (dict): A dict of brain name to measure value.
            reward_buff_sizes (dict): A dict of brain names to the size of their
                corresponding reward buffers.

        Returns:
            A dict from brain name to whether that brain's lesson number was
            incremented.

def increment_lessons(self, measure_vals, reward_buff_sizes=None):
        """Attempts to increments all the lessons of all the curriculums in this
        MetaCurriculum. Note that calling this method does not guarantee the
        lesson of a curriculum will increment. The lesson of a curriculum will
        only increment if the specified measure threshold defined in the
        curriculum has been reached and the minimum number of episodes in the
        lesson have been completed.

        Args:
            measure_vals (dict): A dict of brain name to measure value.
            reward_buff_sizes (dict): A dict of brain names to the size of their
                corresponding reward buffers.

        Returns:
            A dict from brain name to whether that brain's lesson number was
            incremented.
        """
        ret = {}
        if reward_buff_sizes:
            for brain_name, buff_size in reward_buff_sizes.items():
                if self._lesson_ready_to_increment(brain_name, buff_size):
                    measure_val = measure_vals[brain_name]
                    ret[brain_name] = (self.brains_to_curriculums[brain_name]
                                           .increment_lesson(measure_val))
        else:
            for brain_name, measure_val in measure_vals.items():
                ret[brain_name] = (self.brains_to_curriculums[brain_name]
                                       .increment_lesson(measure_val))
        return ret