TypeError: postcss.root is not a constructor

[SSinischo]

Hello, I get the following message output to err executing the following test code:
"TypeError: postcss.root is not a constructor"

'''

const less = require('postcss-less-engine');

var exampleLess = fs.readFileSync(path.join(__dirname, 'less/test.less'), 'utf8');

postcss([
less({ strictMath: true }),
autoprefixer(),
])
.process(exampleLess, { parser: less.parser, from: 'less/test.less' })
.then(function (result) {
console.log(result.css);
}, function(err) {console.log("ERROR!!" + err)});
'''