old_contents: import React from 'react'
  import TOC from './toc'
  
  function Navigation (props) {
    function renderMenu () {
      return (
        <ul className='docs-navigation-menu mobile'>
          {Object.keys(props.docs).map(function (sectionKey, index) {
            return (
              <li key={index} className={`docs-navigation-item${props.sectionName === sectionKey ? ' active' : ''} mobile`}>
                <a href={`/docs/${sectionKey}`}>{sectionKey.replace('_', ' ')}</a>
                {props.sectionName === sectionKey ? <TOC docName={props.docName} sectionName={props.sectionName} sections={props.docs[props.sectionName]} /> : null}
              </li>
            )
          })}
        </ul>
      )
    }
  
    return (
      <div id='navigation-mobile' className='docs-navigation mobile'>
        <div id='hamburger' className='docs-navigation-hamburger'/>
        <div className='docs-navigation-title mobile'>
          {props.sectionName.replace('_', ' ')}
        </div>
        <div className='docs-navigation-float mobile'>
          {renderMenu()}
        </div>
      </div>
    )
  }
  
  export default Navigation
  
new_contents: import React from 'react'
  import TOC from './toc'
  
  function Navigation (props) {
    function renderMenu () {
      return (
        <ul className='docs-navigation-menu mobile'>
          {Object.keys(props.docs).map(function (sectionKey, index) {
            return (
              <li key={index} className={`docs-navigation-item${props.sectionName === sectionKey ? ' active' : ''} mobile`}>
                <a href={`/docs/${sectionKey}`}>{sectionKey.replace('_', ' ')}</a>
                {props.sectionName === sectionKey ? <TOC docName={props.docName} sectionName={props.sectionName} sections={props.docs[props.sectionName]} /> : null}
              </li>
            )
          })}
        </ul>
      )
    }
  
    return (
      <div id='navigation-mobile' className='docs-navigation mobile'>
        <div id='hamburger' className='docs-navigation-hamburger' />
        <div className='docs-navigation-title mobile'>
          {props.sectionName.replace('_', ' ')}
        </div>
        <div className='docs-navigation-float mobile'>
          {renderMenu()}
        </div>
      </div>
    )
  }
  
  export default Navigation
  
subject: correct lint error