KeyManager[] getKeyManagers() throws GeneralSecurityException, IOException {
        if (KEY_MANAGERS != null) {
            return KEY_MANAGERS;
        }
        // find KeyStore, KeyManagers
        String keystore = System.getProperty("javax.net.ssl.keyStore");
        if (keystore == null) {
            return null;
        }
        String keystorepwd = System.getProperty("javax.net.ssl.keyStorePassword");
        char[] pwd = (keystorepwd == null) ? null : keystorepwd.toCharArray();

        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
        try (InputStream is = new BufferedInputStream(new FileInputStream(keystore))) {
            ks.load(is, pwd);
        }

        String kmfAlg = KeyManagerFactory.getDefaultAlgorithm();
        KeyManagerFactory kmf = KeyManagerFactory.getInstance(kmfAlg);
        kmf.init(ks, pwd);
        KEY_MANAGERS = kmf.getKeyManagers();
        return KEY_MANAGERS;
    }
DefaultSSLContextImpl delegates the work to the super class since there
is no way to put a synchronized around both the call to super and the
rest of this constructor to guarantee that we don't have races in
creating the state shared between all default SSLContexts.
common/src/main/java/org/conscrypt/DefaultSSLContextImpl.java