### Question:
StringOption extends ValueOption<StringOption> { @Deprecated public StringOption modify(Text newText) { if (newText == null) { this.nullValue = true; } else { this.nullValue = false; entity.set(newText); } return this; } StringOption();  StringOption(String textOrNull); Text get(); String getAsString(); StringBuilder appendTo(StringBuilder buffer); boolean isEmpty(); Text or(Text alternate); String or(String alternate); void reset(); @Deprecated StringOption modify(Text newText); @Deprecated StringOption modify(String newText); @Deprecated StringOption modify(byte[] utf8, int offset, int length); @Override @Deprecated void copyFrom(StringOption optionOrNull); @Override int hashCode(); @Override boolean equals(Object obj); boolean has(String other); boolean has(Text other); boolean contains(String sub); boolean contains(StringOption sub); boolean startsWith(String prefix); boolean startsWith(StringOption prefix); boolean endsWith(String suffix); boolean endsWith(StringOption suffix); @Override int compareTo(WritableRawComparable o); @Override String toString(); @Override void write(DataOutput out); @SuppressWarnings("deprecation") @Override void readFields(DataInput in); @SuppressWarnings("deprecation") @Override int restore(byte[] bytes, int offset, int limit); @Override int getSizeInBytes(byte[] buf, int offset); @Override int compareInBytes(byte[] b1, int o1, byte[] b2, int o2); static int getBytesLength(byte[] bytes, int offset, int length); static int compareBytes(
            byte[] b1, int s1, int l1,
            byte[] b2, int s2, int l2);  }### Answer:
@Test public void modifyNull() { StringOption option = new StringOption(); option.modify("NotNull"); assertThat(option.isNull(), is(false)); option.modify((String) null); assertThat(option.isNull(), is(true)); option.modify("NotNull"); option.modify((Text) null); assertThat(option.isNull(), is(true)); }
@Test public void modify_bytes() { StringOption option = new StringOption(); byte[] bytes = "hello".getBytes(StringOptionUtil.ENCODING); option.modify(bytes, 0, bytes.length); assertThat(option, is(new StringOption("hello"))); }
@Test public void compare() { StringOption a = new StringOption(); StringOption b = new StringOption(); StringOption c = new StringOption(); StringOption d = new StringOption(); a.modify("ba"); b.modify("aa"); c.modify("ab"); d.modify("ba"); assertThat(compare(a, b), greaterThan(0)); assertThat(compare(b, c), lessThan(0)); assertThat(compare(c, a), lessThan(0)); assertThat(compare(a, c), greaterThan(0)); assertThat(compare(b, a), lessThan(0)); assertThat(compare(c, b), greaterThan(0)); assertThat(compare(a, a), is(0)); assertThat(compare(a, d), is(0)); }
@Test public void compareNull() { StringOption a = new StringOption(); StringOption b = new StringOption(); StringOption c = new StringOption(); a.modify("a"); assertThat(compare(a, b), greaterThan(0)); assertThat(compare(b, a), lessThan(0)); assertThat(compare(b, c), is(0)); }