code: public static @Nullable String readNullableString(DataInputView in) throws IOException {
  		if (in.readBoolean()) {
  			return readString(in);
  		} else {
  			return null;
  		}
  	}
docs: Reads a String from the given input. The string may be null and must have been written with
  {@link #writeNullableString(String, DataOutputView)}.
  
  @param in The input to read from.
  @return The deserialized string, or null.
  
  @throws IOException Thrown, if the reading or the deserialization fails.