@type retry_after_fun() :: (term() -> non_neg_integer() | nil)

@type retry_on_fun() :: (term() -> boolean())

@type t() :: %Foundation.Retry.Policy{
  backoff: Foundation.Backoff.Policy.t(),
  max_attempts: non_neg_integer() | :infinity,
  max_elapsed_ms: non_neg_integer() | nil,
  progress_timeout_ms: non_neg_integer() | nil,
  retry_after_ms_fun: retry_after_fun() | nil,
  retry_on: retry_on_fun()
}