code: func (w *Wallet) SignText(account accounts.Account, text []byte) ([]byte, error) {
  	return w.signHash(account, accounts.TextHash(text))
  }
docs: // SignText requests the wallet to sign the hash of a given piece of data, prefixed
  // by the Ethereum prefix scheme
  // It looks up the account specified either solely via its address contained within,
  // or optionally with the aid of any location metadata from the embedded URL field.
  //
  // If the wallet requires additional authentication to sign the request (e.g.
  // a password to decrypt the account, or a PIN code o verify the transaction),
  // an AuthNeededError instance will be returned, containing infos for the user
  // about which fields or actions are needed. The user may retry by providing
  // the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
  // the account in a keystore).