def sorting=(val)
      val = [val] if val.is_a? Hash
      sorting.set(*val)
    end
def sorting=(val)
      val = [val] if val.is_a? Hash
      sorting.set(*val)
    end
the default sorting.
 should be a hash of {column_name => direction}, e.g. {:a => 'desc', :b => 'asc'}.
 for backwards compatibility, it may be an array of hashes of {column_name => direction}, e.g. [{:a => 'desc'}, {:b => 'asc'}].
 to just sort on one column, you can simply provide a hash, e.g. {:a => 'desc'}.