sort
Defines the sortable property and behavior.
    set.props.sort(prop, [sortFunc])
  
  Defines the sortable property and behavior.
var algebra = new set.Algebra(set.props.sort("sortBy"));
algebra.index(
  {sortBy: "name desc"},
  [{name: "Meyer"}],
  {name: "Adams"}) //-> 1
algebra.index(
  {sortBy: "name"},
  [{name: "Meyer"}],
  {name: "Adams"}) //-> 0
  
  Parameters
- prop 
{String}:The sortable property.
 - sortFunc 
{function(sortPropValue, item1, item2)}:The sortable behavior. The default behavior assumes the sort property value looks like
PROPERTY DIRECTION(ex:name desc).