code: function parseExtraVars(extraVars) {
    if (!(_.isString(extraVars))) {
      return undefined;
    }
    const myVars = _.split(extraVars, ' ').map(it => {
      const v = _.split(it, '=');
      if ( v.length != 2 )
        throw new Error("Can't parse variable");
      return v;
    });
    return _.fromPairs(myVars);
  }
docs: given a string of one or more key-value pairs separated by '=', convert and return object