assertSame("abcba", StringUtils.replaceChars("abcba", "z", "w"));
assertEquals("abcba", StringUtils.replaceChars("abcba", "z", "w"));     assertEquals("jelly", StringUtils.replaceChars("hello", "ho", "jy")); assertEquals("ayzya", StringUtils.replaceChars("abcba", "bc", "yz")); assertEquals("ayya", StringUtils.replaceChars("abcba", "bc", "y")); assertEquals("ayzya", StringUtils.replaceChars("abcba", "bc", "yzx"));   assertEquals("bcc", StringUtils.replaceChars("abc", "ab", "bc")); assertEquals("q651.506bera", StringUtils.replaceChars("d216.102oren", "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789", "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM567891234"));
    public void testReplaceChars_StringStringString() {        assertEquals("jelly", StringUtils.replaceChars("hello", "ho", "jy"));        assertEquals(null, StringUtils.replaceChars(null, null, null));        assertEquals(null, StringUtils.replaceChars(null, "", null));        assertEquals(null, StringUtils.replaceChars(null, "a", null));        assertEquals(null, StringUtils.replaceChars(null, null, ""));        assertEquals(null, StringUtils.replaceChars(null, null, "x"));                assertEquals("", StringUtils.replaceChars("", null, null));        assertEquals("", StringUtils.replaceChars("", "", null));        assertEquals("", StringUtils.replaceChars("", "a", null));        assertEquals("", StringUtils.replaceChars("", null, ""));        assertEquals("", StringUtils.replaceChars("", null, "x"));        assertEquals("abc", StringUtils.replaceChars("abc", null, null));        assertEquals("abc", StringUtils.replaceChars("abc", null, ""));        assertEquals("abc", StringUtils.replaceChars("abc", null, "x"));                assertEquals("abc", StringUtils.replaceChars("abc", "", null));        assertEquals("abc", StringUtils.replaceChars("abc", "", ""));        assertEquals("abc", StringUtils.replaceChars("abc", "", "x"));                assertEquals("ac", StringUtils.replaceChars("abc", "b", null));        assertEquals("ac", StringUtils.replaceChars("abc", "b", ""));        assertEquals("axc", StringUtils.replaceChars("abc", "b", "x"));                assertEquals("ayzya", StringUtils.replaceChars("abcba", "bc", "yz"));        assertEquals("ayya", StringUtils.replaceChars("abcba", "bc", "y"));        assertEquals("ayzya", StringUtils.replaceChars("abcba", "bc", "yzx"));                assertSame("abcba", StringUtils.replaceChars("abcba", "z", "w"));    }