old_contents: import React, { Component } from "react";
  import { Col } from "reactstrap";
  
  class StoryIcon extends Component {
    render() {
      return (
        <Col xs={2} md={4} className="text-center">
          {this.props.children}
        </Col>
      );
    }
  }
  
  export default StoryIcon;
  
new_contents: import React from "react";
  import { Col } from "reactstrap";
  
  const StoryIcon = props => {
    return (
      <Col xs={2} md={4} className="text-center">
        {props.children}
      </Col>
    );
  };
  
  export default StoryIcon;
  
subject: convert StoryIcon to functional component