Instructs the SelectionModel whether or not to inject the checkbox header
automatically or not. (Note: By not placing...
Instructs the SelectionModel whether or not to inject the checkbox header
automatically or not. (Note: By not placing the checkbox in manually, the
grid view will need to be rendered 2x on initial render.)
Supported values are a Number index, false and the strings 'first' and 'last'.
Default is 0.