Removed unused methods on NdOverlay
Removed unused methods on NdOverlay

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