No variables when using only "default" theme

[donwojtallo]

If I provide in themes only the default one (or if I do not provide any theme) I get this object from useTheme():

{
  name: "default"
  themes: [
    name: "default"
    variables: {}
  ]
}

Please note that there are no variables. If I add any other theme the problem disappears (the variables are populated). Maybe using this lib with just one theme is not really useful, but I think this could be supported just for consistency.