'Helper function for replace_route_table_association and
replace_route_table_association_with_assoc. Should not be used directly.
:type association_id: str
:param association_id: The ID of the existing association to replace.
:type route_table_id: str
:param route_table_id: The route table to ID to be used in the
association.
:type dry_run: bool
:param dry_run: Set to True if the operation should not actually run.
:rtype: ResultSet
:return: ResultSet of Amazon resposne'

def _replace_route_table_association(self, association_id, route_table_id, dry_run=False):

    params = {'AssociationId': association_id, 'RouteTableId': route_table_id}
    if dry_run:
        params['DryRun'] = 'true'
    return self.get_object('ReplaceRouteTableAssociation', params, ResultSet)
