sub BUILD {
  my $self = shift;
  my $mode = $self->get_mode();

  # normally roles are not used/required, but since we manipulate this
  # class' roles at runtime we need to require the role
  if ($mode =~ /R/xmsi) {
    require TLA::Datastore::_readable;
    TLA::Datastore::_readable->meta->apply($self);
  }
  if ($mode =~ /W/xmsi) {
    require TLA::Datastore::_writeable;
    TLA::Datastore::_writeable->meta->apply($self);
  }
  if ($mode =~ /X/xmsi) {
    require TLA::Datastore::_execute;
    TLA::Datastore::_execute->meta->apply($self);
  }
  return;
}