@Test
public void escapeCsvGarbageFree() {

    // 'StringUtil#escapeCsv()' should return same string object if string didn't changing.
    assertSame("1", StringUtil.escapeCsv("1", true));
    assertSame(" 123 ", StringUtil.escapeCsv(" 123 ", false));
    assertSame("\" 123 \"", StringUtil.escapeCsv("\" 123 \"", true));
    assertSame("\"\"", StringUtil.escapeCsv("\"\"", true));
    assertSame("123 \"\"", StringUtil.escapeCsv("123 \"\"", true));
    assertSame("123\"\"321", StringUtil.escapeCsv("123\"\"321", true));
    assertSame("\"123\"\"321\"", StringUtil.escapeCsv("\"123\"\"321\"", true));
}