PreferHTTPTransport tells the roundtripper constructor to prefer using an HTTP transport (as opposed to a libp2p stream transport).

ServerMustAuthenticatePeerID tells the roundtripper constructor that we MUST authenticate the Server's PeerID.

LegacyWellKnownProtocols refer to a the well-known resource used in an early draft of the libp2p+http spec.

Host is a libp2p host for request/responses with HTTP semantics.

ProtocolMeta is metadata about a protocol.

WellKnownHandler is an http.Handler that serves the well-known resource.

PeerMetadataGetter lets RoundTrippers implement a specific way of caching a peer's protocol mapping.