message: Throw error when theme is empty object
diff: @@ -14,7 +14,7 @@ ThemeProvider.defaultProps = {
  const useTheme = () => {
  const theme = useContext(ThemeContext);
  - if (theme === undefined) {
  + if (theme === undefined || Object.keys(theme).length === 0 ) {
  throw new Error("useTheme must be used within a ThemeProvider");
  }
  return theme;
  