docs: protected String getEnv(final String key) {
          if (key == null)
              return null;
  
          String value = null;
          try {
              value = AccessController.doPrivileged(new java.security.PrivilegedExceptionAction<String>() {
                  @Override
                  public String run() throws Exception {
                      return System.getenv(key);
                  }
              });
          } catch (Exception ex) {
              // Oh well.
          }
  
          return value;
      }