code: protected X509Credential loadProxyCredential(String proxyPath) {
  
      PEMCredential cred = null;
  
      listener.notifyCredentialLookup(proxyPath);
  
      try {
  
        FilePermissionHelper.checkProxyPermissions(proxyPath);
        cred = new PEMCredential(new FileInputStream(proxyPath), (char[]) null);
        listener.notifyLoadCredentialSuccess(proxyPath);
  
      } catch (Throwable t) {
  
        listener.notifyLoadCredentialFailure(t, proxyPath);
      }
  
      return cred;
    }
docs: Loads an X.509 proxy credential and notifies the registered
  {@link LoadCredentialsEventListener} of the load operation outcome.
  
  @param proxyPath
  the path to the proxy credential
  @return the loaded {@link X509Credential}, or <code>null</code> if the
  credential couldn't be loaded