@typedef FIRUserUpdateCallback @brief The type of block invoked when a request to update the current user is completed.

@typedef FIRAuthStateDidChangeListenerHandle @brief The type of handle returned by Auth.addAuthStateDidChangeListener(_:).

@typedef FIRAuthStateDidChangeListenerBlock @brief The type of block which can be registered as a listener for auth state did change events.

- parameter: auth The Auth object on which state changes occurred.
- parameter: user Optionally; the current signed in user, if any.

@typedef FIRIDTokenDidChangeListenerHandle @brief The type of handle returned by Auth.addIDTokenDidChangeListener(_:).

@typedef FIRIDTokenDidChangeListenerBlock @brief The type of block which can be registered as a listener for ID token did change events.

- parameter: auth The Auth object on which ID token changes occurred.
- parameter: user Optionally; the current signed in user, if any.

@typedef FIRAuthDataResultCallback @brief The type of block invoked when sign-in related events complete.

- parameter: authResult Optionally; Result of sign-in request containing both the user and
   the additional user info associated with the user.
- parameter: error Optionally; the error which occurred - or nil if the request was successful.

@typedef FIRAuthResultCallback @brief The type of block invoked when sign-in related events complete.

- parameter: user Optionally; the signed in user, if any.
- parameter: error Optionally; if an error occurs, this is the NSError object that describes the
    problem. Set to nil otherwise.

@typedef FIRProviderQueryCallback @brief The type of block invoked when a list of identity providers for a given email address is requested.

- parameter: providers Optionally; a list of provider identifiers, if any.
    - see: GoogleAuthProviderID etc.
- parameter: error Optionally; if an error occurs, this is the NSError object that describes the
    problem. Set to nil otherwise.

@typedef FIRSignInMethodQueryCallback @brief The type of block invoked when a list of sign-in methods for a given email address is requested.

@typedef FIRSendPasswordResetCallback @brief The type of block invoked when sending a password reset email.

- parameter: error Optionally; if an error occurs, this is the NSError object that describes the
    problem. Set to nil otherwise.

@typedef FIRSendSignInLinkToEmailCallback @brief The type of block invoked when sending an email sign-in link email.

@typedef FIRConfirmPasswordResetCallback @brief The type of block invoked when performing a password reset.

- parameter: error Optionally; if an error occurs, this is the NSError object that describes the
    problem. Set to nil otherwise.

@typedef FIRVerifyPasswordResetCodeCallback @brief The type of block invoked when verifying that an out of band code should be used to perform password reset.

- parameter: email Optionally; the email address of the user for which the out of band code applies.
- parameter: error Optionally; if an error occurs, this is the NSError object that describes the
    problem. Set to nil otherwise.

@typedef FIRApplyActionCodeCallback @brief The type of block invoked when applying an action code.

- parameter: error Optionally; if an error occurs, this is the NSError object that describes the
    problem. Set to nil otherwise.

Undocumented

@typedef FIRAuthCredentialCallback @brief The type of block invoked when obtaining an auth credential. - parameter: credential The credential obtained. - parameter: error The error that occurred if any.

@typedef FIRGameCenterCredentialCallback @brief The type of block invoked when the Game Center credential code has finished. - parameter: credential On success, the credential will be provided, nil otherwise. - parameter: error On error, the error that occurred, nil otherwise.

@typedef FIRMultiFactorSessionCallback @brief The callback that triggered when a developer calls getSessionWithCompletion. This type is available on iOS and macOS. - parameter: session The multi factor session returned, if any. - parameter: error The error which occurred, if any.

@typedef FIRVerificationResultCallback @brief The type of block invoked when a request to send a verification code has finished. This type is available on iOS only.

- parameter: verificationID On success, the verification ID provided, nil otherwise.
- parameter: error On error, the error that occurred, nil otherwise.