libserf-dev 1.3.9-4build1 (s390x binary) in ubuntu bionic

 serf library is a C-based HTTP client library built upon the Apache
 Portable Runtime (APR) library. It multiplexes connections, running the
 read/write communication asynchronously. Memory copies and
 transformations are kept to a minimum to provide high performance
 operation.
 .
 This package contains development headers for serf.