/// Creates a column for a flex grid. By default, the column will stretch to the full width of its container, but this can be overridden with sizing classes, or by using the `unstack` class on the parent flex row.
///
/// @param {Mixed} $columns [expand] - Width of the column. Refer to the `flex-grid-column()` function to see possible values.
-/// @param {Number} $gutter [$grid-column-gutter] - Space between columns, added as a left and right padding.
+/// @param {Number|Map} $gutters [$grid-column-gutter] - Map or single value for gutters width. See the `grid-column-gutter` mixin.
@mixin flex-grid-column(
$columns: expand,
$gutters: $grid-column-gutter