@type jitter_strategy() :: :none | :factor | :additive | :range

@type rand_fun() :: (-> float()) | (pos_integer() -> pos_integer())

@type strategy() :: :exponential | :linear | :constant

@type t() :: %Foundation.Backoff.Policy{
  base_ms: pos_integer(),
  jitter: float() | {float(), float()},
  jitter_strategy: jitter_strategy(),
  max_ms: pos_integer() | nil,
  rand_fun: rand_fun(),
  strategy: strategy()
}