to Export columns in collection mode

kedilikupa

When i use tabletool plugin's collection option ( "sExtends": "collection" ) , i cannot filter the columns with the help of the mColumns option.

When this code below works.
{
"sExtends": "pdf",
"sButtonText": "Special columns",
"mColumns": [ 1, 4 ]
}

This code below doesn t work.

{
"sExtends": "collection",
"sButtonText": "Export",
"aButtons": [ "csv", "xls", "pdf" ],
"mColumns": [ 1, 4 ]
}

Thx in advance for your answers.