/usr/include/tumbler-1/tumbler/ is in libtumbler-1-dev 0.1.24-0ubuntu1.
This file is owned by root:root, with mode 0o755.
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/usr/include/tumbler-1/tumbler/tumbler-abstract-thumbnailer.h
/usr/include/tumbler-1/tumbler/tumbler-cache-plugin.h
/usr/include/tumbler-1/tumbler/tumbler-cache.h
/usr/include/tumbler-1/tumbler/tumbler-config.h
/usr/include/tumbler-1/tumbler/tumbler-enum-types.h
/usr/include/tumbler-1/tumbler/tumbler-error.h
/usr/include/tumbler-1/tumbler/tumbler-file-info.h
/usr/include/tumbler-1/tumbler/tumbler-glib-extensions.h
/usr/include/tumbler-1/tumbler/tumbler-marshal.h
/usr/include/tumbler-1/tumbler/tumbler-provider-factory.h
/usr/include/tumbler-1/tumbler/tumbler-provider-plugin.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnail-flavor.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnail.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnailer-provider.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnailer.h
/usr/include/tumbler-1/tumbler/tumbler-util.h
/usr/include/tumbler-1/tumbler/tumbler.h