@Override
    public DescribeDBSubnetGroupsResult describeDBSubnetGroups(DescribeDBSubnetGroupsRequest request) {
        request = beforeClientExecution(request);
        return executeDescribeDBSubnetGroups(request);
    }
<p>
Returns a list of DBSubnetGroup descriptions. If a DBSubnetGroupName is specified, the list will contain only the
descriptions of the specified DBSubnetGroup.
</p>
<p>
For an overview of CIDR ranges, go to the <a
href="http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing">Wikipedia Tutorial</a>.
</p>

@param describeDBSubnetGroupsRequest
@return Result of the DescribeDBSubnetGroups operation returned by the service.
@throws DBSubnetGroupNotFoundException
        <code>DBSubnetGroupName</code> doesn't refer to an existing DB subnet group.
@sample AmazonRDS.DescribeDBSubnetGroups
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/DescribeDBSubnetGroups" target="_top">AWS API
     Documentation</a>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/AmazonRDSClient.java