Error in the documentation of the --merge option of obiselect
--merge=<KEY>
Attribute to merge.
Example:
> obiselect -c seq_length -n 2 -m sample seq1.fasta > seq2.fasta
This command keeps two sequences per sequence length, and records how many times they were observed for each
sample in the new attribute merged_sample.
Should be --merge and not -m in the example