How to - create a mock dicom object

[hsm2k3]

I would like to run a test using this package. How can I mock a dataset?
I know this gives me an empty dataset dataset, _ := dicom.ParseFile("dicom/1.dcm", nil) and what I would like to do is be able to create one that's hard coded.
I'm looking to do something like this:

dataset, _ := dicom.Dataset{tag.PatientName: "John^Doe"}

Would anyone be able to help me with this?