I have developed a CNV detection pipeline for my WES data. While I think it is OK, I would like to test its performance against some synthetic WES data which contains CNVs which I have created synthetically. Does anyone have any experience in generating synthetic WES data based on a FASTQ/ bed file? Or would it be better to spike in duplications or deletions into already existing fastq files which could be used as controls? Any advice on tools which can perform this would be really appeciated.