code: protected X509Credential loadPEMCredential(String privateKeyPath,
      String certificatePath, PasswordFinder pf) {
  
      PEMCredential cred = null;
  
      listener.notifyCredentialLookup(privateKeyPath, certificatePath);
  
      try {
  
        FilePermissionHelper.checkPrivateKeyPermissions(privateKeyPath);
  
        cred = new PEMCredential(new FileInputStream(privateKeyPath),
          new FileInputStream(certificatePath), pf);
  
        listener.notifyLoadCredentialSuccess(privateKeyPath, certificatePath);
  
      } catch (Throwable t) {
  
        listener.notifyLoadCredentialFailure(t, privateKeyPath, certificatePath);
      }
  
      return cred;
  
    }
docs: Loads a PEM X.509 credential and notifies the registered
  {@link LoadCredentialsEventListener} of the load operation outcome.
  
  @param privateKeyPath
  the path to the private key
  @param certificatePath
  the path to the certificate
  @param pf
  a {@link PasswordFinder} used to resolve the private key password
  when needed
  @return the loaded {@link X509Credential}, or <code>null</code> if the
  credential couldn't be loaded