How to use the fela-bindings.createTheme function in fela-bindings

return {
    childContextTypes: {
      ...childContextTypes,
      [THEME_CHANNEL]: PropTypes.object,
      renderer: PropTypes.object,
    },
    contextTypes: {
      ...contextTypes,
      [THEME_CHANNEL]: PropTypes.object,
      renderer: PropTypes.object,
    },
    context: {
      ...context,
      renderer,
      [THEME_CHANNEL]: theme ? createTheme(theme) : null,
    },
    ...otherOptions,
  }
}