Creates the default sort key for an attribute.

  Creates the default sort key for an attribute. Entries will be sorted
according to the specified attribute in ascending order using the
ordering matching rule defined for use with that attribute.
Parameters:
- attrID - The non-null ID of the attribute to be used as a sort key.

  Creates a sort key for an attribute.

  Creates a sort key for an attribute. Entries will be sorted according to
the specified attribute in the specified sort order and using the
specified matching rule, if supplied.
Parameters:
- attrID - The non-null ID of the attribute to be used as a sort key.
- ascendingOrder - If true then entries are arranged in ascending order. Otherwise there are arranged in descending order.
- matchingRuleID - The possibly null ID of the matching rule to use to order the attribute values. If not specified then the ordering matching rule defined for the sort key attribute is used.