tests add for BW_DS_VanderBilt code contribution

[petravanhoudt]

add tests for code from Brian Welch and David Smith from VanderBilt

• add tests

• update json file

• update figures

• update manuscript if we do it before submission

[mjt320]

@petravanhoudt As you suggested, perhaps we should indeed postpone this until post-submission. More important to submit the manuscript.