code: protected HttpClientContext createHttpContext(InternalRequest request) {
          HttpClientContext context = HttpClientContext.create();
          context.setRequestConfig(this.requestConfigBuilder.setExpectContinueEnabled(request.isExpectContinueEnabled())
                  .build());
          if (this.credentialsProvider != null) {
              context.setCredentialsProvider(this.credentialsProvider);
          }
          if (this.config.isProxyPreemptiveAuthenticationEnabled()) {
              AuthCache authCache = new BasicAuthCache();
              authCache.put(this.proxyHttpHost, new BasicScheme());
              context.setAuthCache(authCache);
          }
          return context;
      }
docs: Creates HttpClient Context object based on the internal request.
  
  @param request The internal request.
  @return HttpClient Context object.