**Describe the bug**
Running Jest unit tests with xhr-mock https://github.com/jameslnewell/xhr-mock fail. Reverting to 0.18.0 fixed it.
lib/defaults.js
data = JSON.parse(data);
      } catch (e) {  }
    }
    return data;
  }],
  /**
   * A timeout in milliseconds to abort a request. If set to 0 (default) a
   * timeout is not created.
   */
  timeout: 0,
  xsrfCookieName: 'XSRF-TOKEN',
  xsrfHeaderName: 'X-XSRF-TOKEN',
  maxContentLength: -1,
  validateStatus: function validateStatus(status) {
    return status >= 200 && status < 300;
  }
};
defaults.headers = {
  common: {
    'Accept': 'application/json, text/plain, */*'
  }
};
utils.forEach(['delete', 'get', 'head'], function forEachMethodNoData(method) {
  defaults.headers[method] = {};
});
utils.forEach(['post', 'put', 'patch'], function forEachMethodWithData(method) {
  defaults.headers[method] = utils.merge(DEFAULT_CONTENT_TYPE);
});
module.exports = defaults;