### iterate (current)
for my $oWkSheet (keys %{$oWkBook}){
    for my $oRec (@{$oWkBook->{$oWkSheet}}){
        for my $oFld (keys %{$oRec}){
            $oRec->{$oFld} =~ s/^\s+\n$//;
        };
    };
};