A client config being constructed. A builder can be modified by,
e.g. rustls_client_config_builder_load_roots_from_file. Once you're
done configuring settings, call rustls_client_config_builder_build
to turn it into a *rustls_client_config. This object is not safe
for concurrent mutation. Under the hood, it corresponds to a
Box<ClientConfig>.
<https://docs.rs/rustls/0.20.0/rustls/struct.ConfigBuilder.html>
A client config being constructed. A builder can be modified by, e.g. rustls_client_config_builder_load_roots_from_file. Once you're done configuring settings, call rustls_client_config_builder_build to turn it into a *rustls_client_config. This object is not safe for concurrent mutation. Under the hood, it corresponds to a Box<ClientConfig>. <https://docs.rs/rustls/0.20.0/rustls/struct.ConfigBuilder.html>