I'm trying to use the library, but can't even get started due to an error: "TypeError: KeyEncoder is not a constructor"

To reproduce:

• In a new directory, npm init
• npm i key-encoder
• In index.js, add just the two lines from the README:

var KeyEncoder = require('key-encoder'),
    keyEncoder = new KeyEncoder('secp256k1')

• run "node index.js"

Result:

    keyEncoder = new KeyEncoder('secp256k1')
                 ^

TypeError: KeyEncoder is not a constructor

Expected result: No output.