code: public String getValueString() {
  		if (current == State.KEY) {
  			return valueStr;
  		} else if (current == State.VALUE_STRING) {
  			return valueStr;
  		} else if (current == State.VALUE_NULL) {
  			return null;
  		} else {
  			throw new IllegalStateException("unexpected state. state=" + current);
  		}
  	}
docs: Get the current value as string.<br>
  
  <p>
  Please call if {@link JsonPullParser#getEventType()} returns {@link State#KEY} or
  {@link State#VALUE_STRING}.
  </p>
  
  @return The current value read as string.