/*
 * call-seq:
 *  length
 *
 * Get the length of the node set
 */
static VALUE length(VALUE self)
{
  nokogiriNodeSetTuple *tuple;
  Data_Get_Struct(self, nokogiriNodeSetTuple, tuple);

  return tuple->node_set ? INT2NUM(tuple->node_set->nodeNr) : INT2NUM(0);
}