content: import React from 'react';
  import { Surface, PolarRadiusAxis } from 'recharts';
  
  export default React.createClass({
    render () {
      const ticks = [
        { value: '100', radius: 50 },
        { value: '200', radius: 100 },
        { value: '300', radius: 150 },
        { value: '400', radius: 200 },
        { value: '500', radius: 250 },
        { value: '600', radius: 300 },
      ];
  
      return (
        <Surface width={1000} height={1000}>
          <PolarRadiusAxis
            cx={500}
            cy={500}
            angle={120}
            ticks={ticks}
          />
        </Surface>
      );
    }
  });
  
  