@Override
    public DBSubnetGroup createDBSubnetGroup(CreateDBSubnetGroupRequest request) {
        request = beforeClientExecution(request);
        return executeCreateDBSubnetGroup(request);
    }
<p>
Creates a new DB subnet group. DB subnet groups must contain at least one subnet in at least two AZs in the
Amazon Web Services Region.
</p>

@param createDBSubnetGroupRequest
@return Result of the CreateDBSubnetGroup operation returned by the service.
@throws DBSubnetGroupAlreadyExistsException
        <code>DBSubnetGroupName</code> is already used by an existing DB subnet group.
@throws DBSubnetGroupQuotaExceededException
        The request would result in the user exceeding the allowed number of DB subnet groups.
@throws DBSubnetQuotaExceededException
        The request would result in the user exceeding the allowed number of subnets in a DB subnet groups.
@throws DBSubnetGroupDoesNotCoverEnoughAZsException
        Subnets in the DB subnet group should cover at least two Availability Zones unless there is only one
        Availability Zone.
@throws InvalidSubnetException
        The requested subnet is invalid, or multiple subnets were requested that are not all in a common VPC.
@sample AmazonRDS.CreateDBSubnetGroup
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/CreateDBSubnetGroup" target="_top">AWS API
     Documentation</a>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/AmazonRDSClient.java