+/**
+ * Features used within the channel_type field in an OpenChannel message.
+ *
+ * A channel is always of some known \"type\", describing the transaction formats used and the exact
+ * semantics of our interaction with our peer.
+ *
+ * Note that because a channel is a specific type which is proposed by the opener and accepted by
+ * the counterparty, only required features are allowed here.
+ *
+ * This is serialized differently from other feature types - it is not prefixed by a length, and
+ * thus must only appear inside a TLV where its length is known in advance.
+ */