How to use the keycode-js.KEY_BACK_SPACE function in keycode-js

if (event.keyCode === KeyCode.KEY_UP) {
      stateValue = TimeUtil.incrementSecond(stateValue);
    }

    if (event.keyCode === KeyCode.KEY_DOWN) {
      stateValue = TimeUtil.decrementSecond(stateValue);
    }

    if (previousStateValue !== stateValue) {
      this.handleValueChange(event, TimeUtil.inputType.SECOND, stateValue, this.state.meridiem);
    }

    if (event.keyCode === KeyCode.KEY_LEFT
      || event.keyCode === KeyCode.KEY_DELETE
      || event.keyCode === KeyCode.KEY_BACK_SPACE) {
      this.focusMinuteFromSecond(event);
    }
  }

handleMonthKeyDown(event) {
    const displayFormat = DateInputUtil.computedDisplayFormat(this.props.displayFormat, this.props.intl.locale);

    if (event.keyCode === KeyCode.KEY_BACK_SPACE || event.keyCode === KeyCode.KEY_DELETE) {
      this.handleValueChange(event, DateInputUtil.inputType.MONTH, '');

      if (displayFormat === 'day-month-year' && event.target.value === '') {
        this.focusDay(event);
      }
    }

    if (event.keyCode === KeyCode.KEY_SPACE || event.keyCode === KeyCode.KEY_UP || event.keyCode === KeyCode.KEY_DOWN) {
      this.setState({ isPlaceholderColored: false });
    }
  }

handleKeyDown(event) {
    const {
      children, intl, onDeselect, value,
    } = this.props;

    const { keyCode, target } = event;

    if (keyCode === KeyCode.KEY_SPACE && target !== this.input) {
      event.preventDefault();
      this.openDropdown(event);
    } else if (keyCode === KeyCode.KEY_UP || keyCode === KeyCode.KEY_DOWN) {
      event.preventDefault();
      this.openDropdown(event);
    } else if (keyCode === KeyCode.KEY_BACK_SPACE && !this.state.searchValue && value.length > 0) {
      const lastOptionValue = value[value.length - 1];
      const lastOption = MenuUtil.findByValue(children, lastOptionValue);
      const lastOptionDisplay = lastOption ? lastOption.props.display : lastOptionValue;

      if (this.visuallyHiddenComponent && this.visuallyHiddenComponent.current) {
        this.visuallyHiddenComponent.current.innerText = intl.formatMessage({ id: 'Terra.form.select.unselectedText' }, { text: lastOptionDisplay });
      }

      if (onDeselect) {
        onDeselect(lastOptionValue);
      }
    } else if (keyCode === KeyCode.KEY_ESCAPE) {
      this.closeDropdown();
    }
  }

handleKeyDown(event) {
    const {
      children, intl, onDeselect, value,
    } = this.props;

    const { keyCode, target } = event;

    if (keyCode === KeyCode.KEY_SPACE && target !== this.input) {
      event.preventDefault();
      this.openDropdown(event);
    } else if (keyCode === KeyCode.KEY_UP || keyCode === KeyCode.KEY_DOWN) {
      event.preventDefault();
      this.openDropdown(event);
    } else if (keyCode === KeyCode.KEY_BACK_SPACE && !this.state.searchValue && value.length > 0) {
      const lastOptionValue = value[value.length - 1];
      const lastOption = MenuUtil.findByValue(children, lastOptionValue);
      const lastOptionDisplay = lastOption ? lastOption.props.display : lastOptionValue;

      if (this.visuallyHiddenComponent && this.visuallyHiddenComponent.current) {
        this.visuallyHiddenComponent.current.innerText = intl.formatMessage({ id: 'Terra.form.select.unselectedText' }, { text: lastOptionDisplay });
      }

      if (onDeselect) {
        onDeselect(lastOptionValue);
      }
    } else if (keyCode === KeyCode.KEY_ESCAPE) {
      this.closeDropdown();
    }
  }