content: import React from 'react';
  
  export default children => {
    return (React.Children.map(children, (child,i) => {
      if (!React.isValidElement(child)) return child;
      const first = i===0;
      const last = i===React.Children.count(children)-1;
      if (!first && !last) return child;
      return React.cloneElement(child, {
        first: first,
        last: last,
      });
    }));
  };
  