### Question:
IdentHelper { public static String identPrefix(int level) { if (level < 1) return ""; if (level < IDENT_CACHE_LENGTH) return IDENT_SPACES[level]; StringBuilder builder=new StringBuilder( level*2); while (level >= IDENT_CACHE_LENGTH) { builder.append(IDENT_SPACES[LENGTH_MINUS_ONE]); level = level-LENGTH_MINUS_ONE; } return builder.append(IDENT_SPACES[level]).toString(); } IdentHelper(); static String identPrefix(int level);  }### Answer:
@Test void identPrefix() { IdentHelper identHelper = new IdentHelper(); assertEquals(IdentHelper.identPrefix(-1),""); assertEquals(IdentHelper.identPrefix(0),""); assertEquals(IdentHelper.identPrefix(1)," "); assertEquals(IdentHelper.identPrefix(2)," "); assertEquals(IdentHelper.identPrefix(10)," "); assertEquals(IdentHelper.identPrefix(11)," "); assertEquals(IdentHelper.identPrefix(12)," "); assertEquals(IdentHelper.identPrefix(13)," "); assertEquals(IdentHelper.identPrefix(14)," "); assertEquals(IdentHelper.identPrefix(20)," "); }