feat(core): remove upgrade::transfer module

core/CHANGELOG.md

@@ -4,6 +4,9 @@
   See [PR 4695](https://github.com/libp2p/rust-libp2p/pull/4695).
 - Remove deprecated functions from `ListenerId`.
   See [PR 4736](https://github.com/libp2p/rust-libp2p/pull/4736).
+- Remove `upgrade::transfer` module.
+  See [issue 4011](https://github.com/libp2p/rust-libp2p/issues/4011) for details.
+  See [PR XXXX](https://github.com/libp2p/rust-libp2p/pull/XXXX).
 
 ## 0.40.1
 

core/src/upgrade.rs

@@ -64,7 +64,6 @@ mod error;
 mod pending;
 mod ready;
 mod select;
-mod transfer;
 
 pub(crate) use apply::{
     apply, apply_inbound, apply_outbound, InboundUpgradeApply, OutboundUpgradeApply,
@@ -73,11 +72,7 @@ pub(crate) use error::UpgradeError;
 use futures::future::Future;
 
 pub use self::{
-    denied::DeniedUpgrade,
-    pending::PendingUpgrade,
-    ready::ReadyUpgrade,
-    select::SelectUpgrade,
-    transfer::{read_length_prefixed, read_varint, write_length_prefixed, write_varint},
+    denied::DeniedUpgrade, pending::PendingUpgrade, ready::ReadyUpgrade, select::SelectUpgrade,
 };
 pub use crate::Negotiated;
 pub use multistream_select::{NegotiatedComplete, NegotiationError, ProtocolError, Version};