use provided user ID

    private static final String JSON_FORMAT = "?format=json";

    private String userID;

    public GetPublicKeyOperation(String userID) {

        this.userID = userID;

    }

    /**

     * @param client Client object

     */

                String response = getMethod.getResponseBodyAsString();

                // Parse the response

                String username = client.getCredentials().getUsername();

                JSONObject respJSON = new JSONObject(response);

                String key = (String) respJSON.getJSONObject(NODE_OCS).getJSONObject(NODE_DATA)

                        .getJSONObject(NODE_PUBLIC_KEYS).get(username);

                        .getJSONObject(NODE_PUBLIC_KEYS).get(userID);

                result = new RemoteOperationResult(true, getMethod);

                ArrayList<Object> keys = new ArrayList<>();