public void setAttachmentArn(String attachmentArn) {
        this.attachmentArn = attachmentArn;
    }
<p>
The Amazon Resource Name (ARN) of the cross-account attachment that specifies the resources (endpoints or CIDR
range) that can be added to accelerators and principals that have permission to add them.
</p>

@param attachmentArn
       The Amazon Resource Name (ARN) of the cross-account attachment that specifies the resources (endpoints or
       CIDR range) that can be added to accelerators and principals that have permission to add them.
aws-java-sdk-globalaccelerator/src/main/java/com/amazonaws/services/globalaccelerator/model/CrossAccountResource.java