code: public Relationship findRelationship(GraphDatabaseService executionEngine, AssociationKey associationKey, RowKey rowKey) {
  		Object[] relationshipValues = relationshipValues( associationKey, rowKey );
  		Object[] queryValues = ArrayHelper.concat( associationKey.getEntityKey().getColumnValues(), relationshipValues );
  		Result result = executionEngine.execute( findRelationshipQuery, params( queryValues ) );
  		return singleResult( result );
  	}
docs: Returns the relationship corresponding to the {@link AssociationKey} and {@link RowKey}.
  
  @param executionEngine the {@link GraphDatabaseService} used to run the query
  @param associationKey represents the association
  @param rowKey represents a row in an association
  @return the corresponding relationship