### Question:
MessageFormatter { static void deeplyAppendParameter(final StringBuilder sbuild, final Object o, final Map<Object[], Void> seenMap) { if (o == null) { sbuild.append("null"); return; } if (!o.getClass().isArray()) { safeObjectAppend(sbuild, o); } else { if (o instanceof boolean[]) { booleanArrayAppend(sbuild, (boolean[]) o); } else if (o instanceof byte[]) { byteArrayAppend(sbuild, (byte[]) o); } else if (o instanceof char[]) { charArrayAppend(sbuild, (char[]) o); } else if (o instanceof short[]) { shortArrayAppend(sbuild, (short[]) o); } else if (o instanceof int[]) { intArrayAppend(sbuild, (int[]) o); } else if (o instanceof long[]) { longArrayAppend(sbuild, (long[]) o); } else if (o instanceof float[]) { floatArrayAppend(sbuild, (float[]) o); } else if (o instanceof double[]) { doubleArrayAppend(sbuild, (double[]) o); } else { objectArrayAppend(sbuild, (Object[]) o, seenMap); } } } private  MessageFormatter();   }### Answer:
@Test public void testAppendParameter() { final StringBuilder sbuild = new StringBuilder(); final Map<Object[], Void> seenMap = new HashMap<Object[], Void>(); final boolean[] ob = { true }; MessageFormatter.deeplyAppendParameter(sbuild, ob, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final byte[] ob2 = { (byte) 1 }; MessageFormatter.deeplyAppendParameter(sbuild, ob2, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final char[] oc = { 'a' }; MessageFormatter.deeplyAppendParameter(sbuild, oc, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final short[] os = { (short) 1 }; MessageFormatter.deeplyAppendParameter(sbuild, os, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final int[] oi = { 1 }; MessageFormatter.deeplyAppendParameter(sbuild, oi, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final long[] ol = { 1L }; MessageFormatter.deeplyAppendParameter(sbuild, ol, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final float[] of = { 1.5f }; MessageFormatter.deeplyAppendParameter(sbuild, of, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final double[] od = { 2.5 }; MessageFormatter.deeplyAppendParameter(sbuild, od, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); final Object[] ob3 = { new Object() }; MessageFormatter.deeplyAppendParameter(sbuild, ob3, seenMap); assertTrue(sbuild.length() > 0); sbuild.setLength(0); }