@Override
    public AddRoleToDBInstanceResult addRoleToDBInstance(AddRoleToDBInstanceRequest request) {
        request = beforeClientExecution(request);
        return executeAddRoleToDBInstance(request);
    }
<p>
Associates an Amazon Web Services Identity and Access Management (IAM) role with a DB instance.
</p>
<note>
<p>
To add a role to a DB instance, the status of the DB instance must be <code>available</code>.
</p>
</note>
<p>
This command doesn't apply to RDS Custom.
</p>

@param addRoleToDBInstanceRequest
@return Result of the AddRoleToDBInstance operation returned by the service.
@throws DBInstanceNotFoundException
        <code>DBInstanceIdentifier</code> doesn't refer to an existing DB instance.
@throws DBInstanceRoleAlreadyExistsException
        The specified <code>RoleArn</code> or <code>FeatureName</code> value is already associated with the DB
        instance.
@throws InvalidDBInstanceStateException
        The DB instance isn't in a valid state.
@throws DBInstanceRoleQuotaExceededException
        You can't associate any more Amazon Web Services Identity and Access Management (IAM) roles with the DB
        instance because the quota has been reached.
@sample AmazonRDS.AddRoleToDBInstance
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/AddRoleToDBInstance" target="_top">AWS API
     Documentation</a>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/AmazonRDSClient.java