code: @Override
      public DescribeDBSecurityGroupsResult describeDBSecurityGroups(DescribeDBSecurityGroupsRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeDBSecurityGroups(request);
      }
docs: <p>
  Returns a list of <code>DBSecurityGroup</code> descriptions. If a <code>DBSecurityGroupName</code> is specified,
  the list will contain only the descriptions of the specified DB security group.
  </p>
  
  @param describeDBSecurityGroupsRequest
  @return Result of the DescribeDBSecurityGroups operation returned by the service.
  @throws DBSecurityGroupNotFoundException
  <i>DBSecurityGroupName</i> doesn't refer to an existing DB security group.
  @sample AmazonRDS.DescribeDBSecurityGroups
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/DescribeDBSecurityGroups" target="_top">AWS
  API Documentation</a>