code: function retrieveEJSON() {
    let EJSON = null;
    try {
      EJSON = requireOptional('mongodb-extjson');
    } catch (error) {} // eslint-disable-line
    if (!EJSON) {
      EJSON = {
        parse: noEJSONError,
        deserialize: noEJSONError,
        serialize: noEJSONError,
        stringify: noEJSONError,
        setBSONModule: noEJSONError,
        BSON: noEJSONError
      };
    }
  
    return EJSON;
  }
docs: Facilitate loading EJSON optionally