Correct in the code comments the name of the FormatException (#117)

- FormatException was mistakenly referenced as FormatError
diff --git a/lib/src/authorization_code_grant.dart b/lib/src/authorization_code_grant.dart
index 4a7ef8a..fafa5f7 100644
--- a/lib/src/authorization_code_grant.dart
+++ b/lib/src/authorization_code_grant.dart
@@ -221,10 +221,10 @@
   /// [getAuthorizationUrl] is called, or to call it after
   /// [handleAuthorizationCode] is called.
   ///
-  /// Throws [FormatError] if [parameters] is invalid according to the OAuth2
+  /// Throws [FormatException] if [parameters] is invalid according to the OAuth2
   /// spec or if the authorization server otherwise provides invalid responses.
   /// If `state` was passed to [getAuthorizationUrl], this will throw a
-  /// [FormatError] if the `state` parameter doesn't match the original value.
+  /// [FormatException] if the `state` parameter doesn't match the original value.
   ///
   /// Throws [AuthorizationException] if the authorization fails.
   Future<Client> handleAuthorizationResponse(
@@ -273,7 +273,7 @@
   /// [getAuthorizationUrl] is called, or to call it after
   /// [handleAuthorizationCode] is called.
   ///
-  /// Throws [FormatError] if the authorization server provides invalid
+  /// Throws [FormatException] if the authorization server provides invalid
   /// responses while retrieving credentials.
   ///
   /// Throws [AuthorizationException] if the authorization fails.
diff --git a/lib/src/client.dart b/lib/src/client.dart
index dc50e43..1dd2282 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -142,7 +142,7 @@
   ///
   /// This will throw a [StateError] if the [Credentials] can't be refreshed, an
   /// [AuthorizationException] if refreshing the credentials fails, or a
-  /// [FormatError] if the authorization server returns invalid responses.
+  /// [FormatException] if the authorization server returns invalid responses.
   ///
   /// You may request different scopes than the default by passing in
   /// [newScopes]. These must be a subset of the scopes in the
diff --git a/lib/src/credentials.dart b/lib/src/credentials.dart
index 2acc8f2..2c2ac51 100644
--- a/lib/src/credentials.dart
+++ b/lib/src/credentials.dart
@@ -201,7 +201,7 @@
   /// This throws an [ArgumentError] if [secret] is passed without [identifier],
   /// a [StateError] if these credentials can't be refreshed, an
   /// [AuthorizationException] if refreshing the credentials fails, or a
-  /// [FormatError] if the authorization server returns invalid responses.
+  /// [FormatException] if the authorization server returns invalid responses.
   Future<Credentials> refresh(
       {String? identifier,
       String? secret,