### Question:
LevenshteinSimilarity extends AbstractStringMetric { @Override public double getSimilarity(String s1, String s2) { Validate.notNull(s1, "s1 must not be null"); Validate.notNull(s2, "s2 must not be null"); if (s1.equals(s2)) { return 1; } int distance = StringUtils.getLevenshteinDistance(s1, s2); int maxLength = Math.max(s1.length(), s2.length()); if (maxLength == 0) { return 1; } return 1 - (double)distance / maxLength; }  @Override double getSimilarity(String s1, String s2); @Override String toString();  }### Answer:
@Test public void testLevenshteinSimilarity() { LevenshteinSimilarity similarity = new LevenshteinSimilarity(); assertEquals(0.64, similarity.getSimilarity("Levenshtein", "Lenvinsten"), 0.01); assertEquals(0.82, similarity.getSimilarity("Levenshtein", "Levensthein"), 0.01); assertEquals(0.91, similarity.getSimilarity("Levenshtein", "Levenshten"), 0.01); assertEquals(1, similarity.getSimilarity("Levenshtein", "Levenshtein"), 0.01); assertEquals(1, similarity.getSimilarity("", ""), 0.01); }