How to use the omi.createElement function in omi

// Icon - Still show loading icon when loading without showIcon
    let $icon;

    if (showIcon) {
      const currentIcon = icon || treeIcon;

      $icon = currentIcon ? (
        <span>
          {typeof currentIcon === 'function' ?
            omi.createElement(currentIcon, {
              ...this.props,
            }) : currentIcon}
        </span>
      ) : this.renderIcon();
    } else if (loadData &amp;&amp; loading) {
      $icon = this.renderIcon();
    }

    // Title
    const $title = <span>{title}</span>;

    return (

switcherIcon: switcherIconFromProps,
    } = this.props;
    const {
      omiTree: {
        prefixCls,
        switcherIcon: switcherIconFromCtx,
      }
    } = this.store;

    const switcherIcon = switcherIconFromProps || switcherIconFromCtx;

    if (this.isLeaf()) {
      return (
        <span>
          {typeof switcherIcon === 'function' ?
            omi.createElement(switcherIcon, { ...this.props, isLeaf: true }) : switcherIcon}
        </span>
      );
    }

    const switcherCls = classNames(`${prefixCls}-switcher`, `${prefixCls}-switcher_${expanded ? ICON_OPEN : ICON_CLOSE}`);
    return (
      <span>
        {typeof switcherIcon === 'function' ?
          omi.createElement(switcherIcon, { ...this.props, isLeaf: false }) : switcherIcon}
      </span>
    );
	}