@Test
void isValidURL() {

    String protocolRelativeURL = "//localhost:8080/path1%20path2/path3?k1=v1%20v2&k2=v1+v2#f1/f2";
    assertThat(fragment.isValidURL(protocolRelativeURL)).isTrue();
    String httpsURL = "http://example.com/:@-._~!$&'()*+,=;:@-._~!$&'()*+,=:@-._~!$&'()*+,==?/?:@-._~!$'()*+,;=/?:@-._~!$'()*+,;==#/?:@-._~!$&'()*+,;=";
    assertThat(fragment.isValidURL(httpsURL)).isTrue();
    String dataImageURL = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==";
    assertThat(fragment.isValidURL(dataImageURL)).isTrue();
    assertFalse(fragment.isValidURL(null));
}