## session
 
 DuplicatedKey
- **interface**: `session.DuplicatedKey.is`
- **summary**:    Registered duplicate key. 
 
 InvalidProof
- **interface**: `session.InvalidProof.is`
- **summary**:    Invalid ownership proof. 
 
 NoAccount
- **interface**: `session.NoAccount.is`
- **summary**:    Key setting account is not live, so it's impossible to associate keys. 
 
 NoAssociatedValidatorId
- **interface**: `session.NoAssociatedValidatorId.is`
- **summary**:    No associated validator ID for account. 
 
 NoKeys
- **interface**: `session.NoKeys.is`
- **summary**:    No keys are associated with this account.