text: 
  import React from "react";
  import PropTypes from "prop-types";
  
  import BigBox from "./BigBox";
  
  import styles from "./VBox.module.css";
  
  
  function _wrap(child, i) {
      if (!child) {
          return null;
      }
      else if (child.type === BigBox) {
          return child;
      }
      else {
          return (
              <div key={i} className={styles.child}>
                  {child}
              </div>);
      }
  }
  
  
  class VBox extends React.Component {
      render(){
          let parts = [];
  
          for (let i = 0; i < this.props.children.length; ++i) {
              if (this.props.children[i] !== null) {
                  parts.push(_wrap(this.props.children[i], i));
              }
          }
  
          return (
              <div className={styles.vbox}>
                  {parts}
              </div>);
      }
  }
  
  
  VBox.propTypes = {
      children: PropTypes.any,
  }
  
  export default VBox;
  