code: function formatKey(key) {
    key = key.toLowerCase()
    // Don't capitalize -ms- prefix
    if (/^-ms-/.test(key)) key = key.substr(1)
    return t.identifier(hyphenToCamelCase(key))
  }
docs: Format style key into JSX style object key.
  
  @param {string} key
  @return {string}