urbanecm@ysul:~/Documents/mediawiki-services-parsoid/tools
$ ./fetch-sitematrix.js
module.js:472
    throw err;
    ^

Error: Cannot find module 'core-js/shim'
    at Function.Module._resolveFilename (module.js:470:15)
    at Function.Module._load (module.js:418:25)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/usr/home/urbanecm/Documents/mediawiki-services-parsoid/core-upgrade.js:3:1)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)