Blinnikov

var system = require('system'),
  env = system.env;

/**
 * Wait until the test condition is true or a timeout occurs. Useful for waiting
 * on a server response or for a ui change (fadeIn, etc.) to occur.
 *
 * @param testFx javascript condition that evaluates to a boolean,
 * it can be passed in as a string (e.g.: "1 == 1" or "$('#bar').is(':visible')" or
 * as a callback function.

Blinnikov

For example, to override the AppBar (https://material-ui-next.com/api/app-bar/) root class we can do the following:

First method (override Material UI classnames):

1 - Add the property classes in the AppBar component:

    <AppBar classes={{root: 'my-root-class'}}