What does mgos_get_min_free_heap_size indicate?

If you are asking a question, please follow this template:

  1. My goal is: Understand what mgos_get_min_free_heap_size indicates
  2. My expectation & question is: What does mgos_get_min_free_heap_size indicate? Is it the minimum amount of free memory need for operation or is it the historical minimum free size recorded since boot?

Thanks