let hg18 =     let hg18_url =       "ftp://gsapubftp-anonymous@ftp.broadinstitute.org/bundle/2.8/hg18/Homo_sapiens_assembly18.fasta.gz" in     let dbsnp_hg18_url =       "ftp://gsapubftp-anonymous@ftp.broadinstitute.org/bundle/2.8/hg18/dbsnp_138.hg18.vcf.gz" in     create Name.hg18       ~ensembl:54       ~species:human       ~metadata:"Provided by the Biokepi library"       ~major_contigs:major_contigs_hg_family       ~fasta:Location.(url hg18_url|> gunzip)       ~dbsnp:Location.(url dbsnp_hg18_url |> gunzip)