### Question:
StringNaturalCompare implements Comparator<String> { public int compare(String s1, String s2) { int result = strnatcmp0(s1, s2, true); return(result); }  int compare(String s1, String s2); static int compareLeft(String s1, int ind1, String s2, int ind2); static int strnatcmp0(String s1, String s2, boolean fold_case);  }### Answer:
@Test public void testStringNaturalComparison() { Comparator<String> comp = new StringNaturalCompare(); String str1 = "1"; String str2 = "2"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "u1"; str2 = "u2"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = " 1"; str2 = " 1"; assertEquals("string natural comparison error for " + str1 + " " + str2, 0, comp.compare(str1, str2)); str1 = " "; str2 = " 1"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = " 1"; str2 = " "; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); str1 = "1.0566"; str2 = "1.057"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "1.057"; str2 = "1.0566"; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); str1 = "1.0566stuff"; str2 = "1.057stuff"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "1.057stuff"; str2 = "1.0566stuff"; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); str1 = "u100"; str2 = "u2"; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); str1 = "u2"; str2 = "u100"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "u100.45367"; str2 = "u100.45467"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "U100"; str2 = "u2"; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); str1 = "U2"; str2 = "u2"; assertEquals("string natural comparison error for " + str1 + " " + str2, 0, comp.compare(str1, str2)); str1 = "200times"; str2 = "200titles"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "200titles"; str2 = "200times"; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); str1 = "201times"; str2 = "2000rew"; assertEquals("string natural comparison error for " + str1 + " " + str2, -1, comp.compare(str1, str2)); str1 = "2000times"; str2 = "201ree"; assertEquals("string natural comparison error for " + str1 + " " + str2, 1, comp.compare(str1, str2)); }