code: @Override
      public CreateTransitGatewayVpcAttachmentResult createTransitGatewayVpcAttachment(CreateTransitGatewayVpcAttachmentRequest request) {
          request = beforeClientExecution(request);
          return executeCreateTransitGatewayVpcAttachment(request);
      }
docs: <p>
  Attaches the specified VPC to the specified transit gateway.
  </p>
  <p>
  If you attach a VPC with a CIDR range that overlaps the CIDR range of a VPC that is already attached, the new VPC
  CIDR range is not propagated to the default propagation route table.
  </p>
  <p>
  To send VPC traffic to an attached transit gateway, add a route to the VPC route table using <a>CreateRoute</a>.
  </p>
  
  @param createTransitGatewayVpcAttachmentRequest
  @return Result of the CreateTransitGatewayVpcAttachment operation returned by the service.
  @sample AmazonEC2.CreateTransitGatewayVpcAttachment
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/ec2-2016-11-15/CreateTransitGatewayVpcAttachment"
  target="_top">AWS API Documentation</a>