content: 
  /** @jsx h */
  
  import React from 'react'
  import h from '../helpers/h'
  
  export const rules = [
    {
      serialize(obj, children) {
        if (obj.kind == 'block' && obj.type == 'paragraph') {
          return React.createElement('p', { 'data-thing': obj.data.get('thing') }, children)
        }
      }
    }
  ]
  
  export const input = (
    <state>
      <document>
        <paragraph thing="value">
          one
        </paragraph>
      </document>
    </state>
  )
  
  export const output = `
  <p data-thing="value">one</p>
  `.trim()
  