Deletes the current selection. If there is no selection in an editor window, the cells under the multiple cursors are deleted.
Complexity: constant-time to linear-time (depends on the number of blocks in a current selection or the number of multiple cursors).
After deleting data, remaining data is shifted to fill all gaps. The size of the file is then reduced to compensate for removed data.
Scripts may use the IDocumentView.clearAsync method to execute this command.