text: import React from 'react';
  import {Helmet} from "react-helmet";
  import PropTypes from 'prop-types';
  
  export default function Head() {
      const title = 'title';
      const description = 'description';
      const userLanguage = 'en';
      return (
          <Helmet>
              {/* Use minimum-scale=1 to enable GPU rasterization. */}
              <meta name="viewport" content="minimum-scale=1, initial-scale=1, width=device-width"/>
              <title>{title}</title>
              <meta name="description" content={description}/>
              {/* Twitter */}
              <meta name="twitter:card" content="summary"/>
              <meta name="twitter:site" content="@MaterialUI"/>
              <meta name="twitter:title" content={title}/>
              <meta name="twitter:description" content={description}/>
              <meta name="twitter:image" content="https://material-ui.com/static/brand.png"/>
              {/* Facebook */}
              <meta property="og:type" content="website"/>
              <meta property="og:title" content={title}/>
              {/*<meta
                  property="og:url"
                  content={`https://material-ui.com${Router._rewriteUrlForNextExport(router.asPath)}`}
              />*/}
              <meta property="og:description" content={description}/>
              <meta property="og:image" content="https://material-ui.com/static/brand.png"/>
              <meta property="og:ttl" content="604800"/>
              {/* Algolia */}
              <meta name="docsearch:language" content={userLanguage}/>
              <meta name="docsearch:version" content="master"/>
          </Helmet>
      );
  }
  
  Head.propTypes = {
      children: PropTypes.node,
      description: PropTypes.string,
      title: PropTypes.string,
  };
  