/usr/include/GNUstep/NGStreams/ is in libsope-dev 2.2.17-1build2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/GNUstep/NGStreams/NGActiveSocket.h
/usr/include/GNUstep/NGStreams/NGBase64Stream.h
/usr/include/GNUstep/NGStreams/NGBufferedStream.h
/usr/include/GNUstep/NGStreams/NGByteBuffer.h
/usr/include/GNUstep/NGStreams/NGByteCountStream.h
/usr/include/GNUstep/NGStreams/NGCTextStream.h
/usr/include/GNUstep/NGStreams/NGCharBuffer.h
/usr/include/GNUstep/NGStreams/NGConcreteStreamFileHandle.h
/usr/include/GNUstep/NGStreams/NGDataStream.h
/usr/include/GNUstep/NGStreams/NGDatagramPacket.h
/usr/include/GNUstep/NGStreams/NGDatagramSocket.h
/usr/include/GNUstep/NGStreams/NGDescriptorFunctions.h
/usr/include/GNUstep/NGStreams/NGFileStream.h
/usr/include/GNUstep/NGStreams/NGFilterStream.h
/usr/include/GNUstep/NGStreams/NGFilterTextStream.h
/usr/include/GNUstep/NGStreams/NGGZipStream.h
/usr/include/GNUstep/NGStreams/NGInternetSocketAddress.h
/usr/include/GNUstep/NGStreams/NGInternetSocketDomain.h
/usr/include/GNUstep/NGStreams/NGLocalSocketAddress.h
/usr/include/GNUstep/NGStreams/NGLocalSocketDomain.h
/usr/include/GNUstep/NGStreams/NGLockingStream.h
/usr/include/GNUstep/NGStreams/NGNet.h
/usr/include/GNUstep/NGStreams/NGNetDecls.h
/usr/include/GNUstep/NGStreams/NGNetUtilities.h
/usr/include/GNUstep/NGStreams/NGPassiveSocket.h
/usr/include/GNUstep/NGStreams/NGSocket.h
/usr/include/GNUstep/NGStreams/NGSocketExceptions.h
/usr/include/GNUstep/NGStreams/NGSocketProtocols.h
/usr/include/GNUstep/NGStreams/NGStream.h
/usr/include/GNUstep/NGStreams/NGStreamExceptions.h
/usr/include/GNUstep/NGStreams/NGStreamPipe.h
/usr/include/GNUstep/NGStreams/NGStreamProtocols.h
/usr/include/GNUstep/NGStreams/NGStreams.h
/usr/include/GNUstep/NGStreams/NGStreamsDecls.h
/usr/include/GNUstep/NGStreams/NGStringTextStream.h
/usr/include/GNUstep/NGStreams/NGTerminalSupport.h
/usr/include/GNUstep/NGStreams/NGTextStream.h
/usr/include/GNUstep/NGStreams/NGTextStreamProtocols.h