Does not compile with use-mock-network flag

The current master commit 27e58732 does not compile with the use-mock-network flag:

$ cabal test 
Preprocessing library network-transport-tcp-0.5.1...
[1 of 4] Compiling Network.Transport.TCP.Mock.Socket ( src/Network/Transport/TCP/Mock/Socket.hs, dist/build/Network/Transport/TCP/Mock/Socket.o )
[2 of 4] Compiling Network.Transport.TCP.Mock.Socket.ByteString ( src/Network/Transport/TCP/Mock/Socket/ByteString.hs, dist/build/Network/Transport/TCP/Mock/Socket/ByteString.o ) [Network.Transport.TCP.Mock.Socket changed]
[3 of 4] Compiling Network.Transport.TCP.Internal ( src/Network/Transport/TCP/Internal.hs, dist/build/Network/Transport/TCP/Internal.o )

src/Network/Transport/TCP/Internal.hs:57:5: error:
    Module
    ‘Network.Transport.TCP.Mock.Socket’
    does not export
    ‘socketPort’

src/Network/Transport/TCP/Internal.hs:59:5: error:
    Module
    ‘Network.Transport.TCP.Mock.Socket’
    does not export
    ‘ShutdownCmd(ShutdownBoth)’

src/Network/Transport/TCP/Internal.hs:61:5: error:
    Module
    ‘Network.Transport.TCP.Mock.Socket’
    does not export
    ‘inet_ntoa’

Start with src/Network/Transport/TCP/Internal.hs and src/Network/Transport/TCP/Mock/Socket.hs, comparing the imports in Internal with the exports provided by the mock socket module. Run cabal test with the use-mock-network flag and confirm that the library compiles without the reported missing-export errors.