@Test
public void testLongestPrefix() {

    Attribute<String, String> stringIdentity = new SelfAttribute<String>(String.class, "identity");
    assertTrue(LongestPrefix.countPrefixChars( "35387123456", "35387") > 0);
    assertEquals(5, LongestPrefix.countPrefixChars( "35387123456", "35387"));
    assertTrue(LongestPrefix.countPrefixChars("35387", "35387") > 0);
    assertEquals(5, LongestPrefix.countPrefixChars("35387", "35387"));
    assertFalse(LongestPrefix.countPrefixChars("35386123456", "35387") > 0);
    assertEquals(0, LongestPrefix.countPrefixChars("35386123456", "35387"));
    assertFalse(LongestPrefix.countPrefixChars("35386123456", "35387") > 0);
    assertEquals(0, LongestPrefix.countPrefixChars("35386123456", "35387"));
    assertFalse(LongestPrefix.countPrefixChars("3538", "35387") > 0);
    assertEquals(0, LongestPrefix.countPrefixChars("3538", "35387"));
}