Added unit tests for duplicate dimension selection
Added unit tests for duplicate dimension selection

mjabri/holoviews,ioam/holoviews,ioam/holoviews,ioam/holoviews,vascotenner/holoviews,basnijholt/holoviews,basnijholt/holoviews,mjabri/holoviews,mjabri/holoviews,vascotenner/holoviews,vascotenner/holoviews,basnijholt/holoviews