text: 
  import React, { PropTypes } from 'react';
  
  const Particle = ({ x, y }) => (
      <circle cx={x} cy={y} r="1.8" />
  );
  
  Particle.propTypes = {
      x: PropTypes.number.isRequired,
      y: PropTypes.number.isRequired
  };
  
  export default Particle;
  