'Associates a network acl with a specific subnet.
:type network_acl_id: str
:param network_acl_id: The ID of the network ACL to associate.
:type subnet_id: str
:param subnet_id: The ID of the subnet to associate with.
:rtype: str
:return: The ID of the association created'

def associate_network_acl(self, network_acl_id, subnet_id):

    acl = self.get_all_network_acls(filters=[('association.subnet-id', subnet_id)])[0]
    association = [association for association in acl.associations if (association.subnet_id == subnet_id)][0]
    params = {'AssociationId': association.id, 'NetworkAclId': network_acl_id}
    result = self.get_object('ReplaceNetworkAclAssociation', params, ResultSet)
    return result.newAssociationId
