The code originates from https://github.com/litespeedtech/ls-hpack and is explicitly documented as not needing to be initialized. x-ref:
LS-HPACK: LiteSpeed HPACK Library
LS-HPACK provides functionality to encode and decode HTTP headers using HPACK compression mechanism specified in RFC 7541.
The API is documented in include/lshpack.h. To see usage examples, see the unit tests.
To build LS-HPACK, you need CMake. The library uses XXHASH at runtime.
The library has been tested on the following platforms:
Copyright (c) 2018 - 2020 LiteSpeed Technologies Inc