How does one use or get started with …theme.mixins.toolbar in Material-ui?

It simply adds a minimum height to an element. It’s useful when you use the AppBar with a content section below, and you want to add a spacer at the top of your content so it doesn’t disappear under the AppBar, for example.

I can’t find specific documentation on it, but there are examples of it being used in the Material-UI layout examples and I believe it might be created by this function.

More specifically, it’s used in the Dashboard example:

toolbarIcon: {
  display: 'flex',
  alignItems: 'center',
  justifyContent: 'flex-end',
  padding: '0 8px',
  ...theme.mixins.toolbar,
},

This would result in something like:

toolbarIcon: {
  display: flex;
  align-items: center;
  justifyContent: flex-end;
  padding: 0 8px;
  min-height: 64px;
}