ar-drop-columns">drop-columns</a> </li><li> <a href="tech.v3.dataset.html#var-drop-missing">drop-missing</a> </li><li> <a href="tech.v3.dataset.html#var-drop-rows">drop-rows</a> </li><li> <a href="tech.v3.dataset.html#var-empty-column-names">empty-column-names</a> </li><li> <a href="tech.v3.dataset.html#var-empty-dataset">empty-dataset</a> </li><li> <a href="tech.v3.dataset.html#var-ensure-array-backed">ensure-array-backed</a> </li><li> <a href="tech.v3.dataset.html#var-filter">filter</a> </li><li> <a href=