atk.RelationSet — a set of atk.Relation
      objects, normally the set of atk.Relation
      objects that an atk.Object
      has.
| class atk.RelationSet( | 
The atk.RelationSet
    held by an object establishes its relationships with objects beyond the
    normal "parent/child" hierarchical relationships that all user interface
    objects have. atk.RelationSet
    objects establish whether objects are labelled or controlled by other
    components, share group membership with other components (for instance
    within a radio-button group), or share content which "flows" between
    them, among other types of possible relationships.
    def contains(relationship)| 
 | one of the Atk Relation Type Constants. | 
| Returns : | Trueifrelationshipis the relationship
          type. | 
Determines whether the relation set contains a relation that
      matches the type specified by
      relationship.
    def remove(relation)| 
 | an atk.Relation | 
Removes a relation from the relation set.
    def add(relation)| 
 | an atk.Relation | 
Add a new atk.Relation
      to the current relation set if it is not already present.
    def get_n_relations()| Returns : | an integer representing the number of relations in the set. | 
Returns the number of relations in a relation set.
    def get_relation(i)| 
 | an index representing a position in the set, starting from 0. | 
| Returns : | the atk.Relation,
          that is the relation at positioniin the
          set. | 
Determines the relation at the specified position in the relation set.
    def get_relation_by_type(relationship)| 
 | one of the Atk Relation Type Constants. | 
| Returns : | an atk.Relation,
          which is a relation matching the specified
          type. | 
Finds a relation that matches the specified type.