### Question:
JsonEscapeHelper { @Nullable public static String jsonEscape (@Nullable final String sInput) { if (StringHelper.hasNoText (sInput)) return sInput; return jsonEscape (sInput.toCharArray ()); } private  JsonEscapeHelper(); static void jsonEscapeToStringBuilder(@Nonnull final char [] aInput, @Nonnull final StringBuilder aSB); @Nullable static String jsonEscape(@Nullable final String sInput); @Nullable static String jsonEscape(@Nullable final char [] aInput); static void jsonEscape(@Nullable final String sInput, @Nonnull final StringBuilder aSB); static void jsonEscapeToWriter(@Nonnull final char [] aInput, @Nonnull @WillNotClose final Writer aWriter); static void jsonEscapeToWriter(@Nullable final String sInput, @Nonnull @WillNotClose final Writer aWriter); static void jsonUnescapeToStringBuilder(@Nonnull final char [] aInput, @Nonnull final StringBuilder aSB); @Nonnull static String jsonUnescape(@Nonnull final String sInput); @Nonnull static String jsonUnescape(@Nonnull final char [] aInput); static final char MASK_CHAR; static final String MASK_STRING; }### Answer:
@Test public void testEscape () { assertEquals (STRING_ESCAPED, JsonEscapeHelper.jsonEscape (STRING_UNESCAPED)); assertEquals ("", JsonEscapeHelper.jsonEscape ("")); }