[ Version ( since = "4.10" ) ]
public Collation collation { get; set; }
The collation method to use for sorting.
The `GTK_COLLATION_NONE` value is useful when the expression already returns collation keys, or strings that need to be compared byte-by-byte.
The default value, `GTK_COLLATION_UNICODE`, compares strings according to the Unicode collation algorithm.