Hmm ... It's impossible ;-) This RPM doesn't exist on any FTP server

Provides :
libwnck3-devel
libwnck3-devel(x86-32)
pkgconfig(libwnck-3.0)

Requires :

libwnck3(x86-32) = 3.20.1-1.el7
libgobject-2.0.so.0
rtld(GNU_HASH)
libpangocairo-1.0.so.0
libgdk_pixbuf-2.0.so.0
libm.so.6
libc.so.6(GLIBC_2.4)
libstartup-notification-1.so.0
pkgconfig(x11)
pkgconfig(pango)
pkgconfig(gtk+-3.0)
libpango-1.0.so.0
libgio-2.0.so.0
rpmlib(PayloadIsXz) <= 5.2-1
libwnck-3.so.0
pkgconfig(cairo)
libgtk-3.so.0
pkgconfig(glib-2.0)
libXrender.so.1
pkgconfig(xres)
libXext.so.6
libc.so.6(GLIBC_2.2)
libc.so.6(GLIBC_2.0)
libXRes.so.1
rpmlib(PayloadFilesHavePrefix) <= 4.0-1
libcairo-gobject.so.2
libX11.so.6
rpmlib(FileDigests) <= 4.6.0-1
rpmlib(CompressedFileNames) <= 3.0.4-1
libcairo.so.2
libgdk-3.so.0
libatk-1.0.so.0
/usr/bin/pkg-config
libglib-2.0.so.0
pkgconfig(libstartup-notification-1.0)
pkgconfig(gobject-2.0)
libc.so.6

Content of RPM :
/usr/bin/wnckprop
/usr/include/libwnck-3.0
/usr/include/libwnck-3.0/libwnck
/usr/include/libwnck-3.0/libwnck/application.h
/usr/include/libwnck-3.0/libwnck/class-group.h
/usr/include/libwnck-3.0/libwnck/libwnck.h
/usr/include/libwnck-3.0/libwnck/pager.h
/usr/include/libwnck-3.0/libwnck/screen.h
/usr/include/libwnck-3.0/libwnck/selector.h
/usr/include/libwnck-3.0/libwnck/tasklist.h
/usr/include/libwnck-3.0/libwnck/util.h
/usr/include/libwnck-3.0/libwnck/version.h
/usr/include/libwnck-3.0/libwnck/window-action-menu.h
/usr/include/libwnck-3.0/libwnck/window.h
/usr/include/libwnck-3.0/libwnck/wnck-enum-types.h
/usr/include/libwnck-3.0/libwnck/workspace.h
/usr/lib/libwnck-3.so
/usr/lib/pkgconfig/libwnck-3.0.pc
/usr/share/gir-1.0/Wnck-3.0.gir
/usr/share/gtk-doc
/usr/share/gtk-doc/html
/usr/share/gtk-doc/html/libwnck-3.0
/usr/share/gtk-doc/html/libwnck-3.0/WnckApplication.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckClassGroup.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckPager.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckScreen.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckSelector.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckTasklist.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckWindow.html
/usr/share/gtk-doc/html/libwnck-3.0/WnckWorkspace.html
There is 36 files more in these RPM.