my @docsObservs;
foreach my $docP (values %{$self->{docs}}) {
  push(@docsObservs, $docP->getObservations());
  die "loop variable is undef after call to getObservations()" if (!defined($docP));
  $docP = undef;
}
map { die "bug after!" if (!defined($_)); } values %{$self->{docs}};