public URL convert(String value) {
        if (isBlank(value)) {
            throw new ParameterException(getErrorString("a blank value", "a valid URL"));
        }

        try {
            return URLUtil.parseURL(value);
        } catch (IllegalArgumentException e) {
            throw new ParameterException(getErrorString(value, "a valid URL"));
        }

    }
@Test
    public void urlIsCreatedFromFilePath() {
        URL url = converter.convert("/path/to/something");

        // on *ux the path part of the URL is equal to the given path
        // on Windows C: is prepended, which is expected
        assertThat(url.getPath(), endsWith("/path/to/something"));
    }