code: public HttpClientBuilder trustKeyStore(URL url, String password) {
  		if (sslHostConfig == null) {
  			throw new IllegalStateException("ssl(String) must be called before this");
  		}
  		sslHostConfig.trustKeyStoreUrl = url;
  		sslHostConfig.trustKeyStorePassword = password;
  		return this;
  	}
docs: Configures a trust store for the current SSL host (see
  {@link #ssl(String)}). If set, SSL client authentication will be used
  when connecting to that host (i.e. the client certificate will be sent).
  
  @param url		URL from which to obtain trust store
  @param password	trust store password
  @return this
  @see #ssl(String)
  @see #keyStore(URL, String)