* A trait which should be implemented to provide feerate information on a number of time
* horizons.
*
+ * If access to a local mempool is not feasible, feerate estimates should be fetched from a set of
+ * third-parties hosting them. Note that this enables them to affect the propagation of your
+ * pre-signed transactions at any time and therefore endangers the safety of channels funds. It
+ * should be considered carefully as a deployment.
+ *
* Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're
* called from inside the library in response to chain events, P2P events, or timer events).
*/