- breakpoints: Object
 - direction: "ltr"
 - components: Object
 - palette: Object
 - spacing: f spacing()
 - shape: Object
 - mixins: Object
 - shadows: Array(25)
 - typography: Object
 - transitions: Object
 - zIndex: Object
 
If you want to learn more about how the theme is assembled, take a look at material-ui/style/createTheme.js, and the related imports which createTheme uses.