These header files are part of the private interface of htslib and not
shipped in the libhts-dev package.  The files in this directory are
a copy of the files found in the source package

   htslib (1.10.2-3) unstable; urgency=medium

Since these are only used for testing but not in the actual program
it should be OK to simply ship this copy here.

 -- Andreas Tille <tille@debian.org>  Fri, 05 Jun 2020 17:53:54 +0200
