Running examples in ‘biofiles-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: filter
> ### Title: Return a subset of features or annotations from a GenBank Record
> ### Aliases: filter select filter,gbFeatureTable-method
> ###   select,gbFeatureTable-method filter,gbRecord-method
> ###   select,gbRecord-method filter,gbRecordList-method
> ###   select,gbRecordList-method
> 
> ### ** Examples
> 
> load(system.file("extdata", "S_cerevisiae_mito.rda", package = "biofiles"))
> 
> ## filter all hydrophobic tRNAs from the yeast mitochondrion
> hydrophobic <- c("Val", "Ile", "Leu", "Met", "Phe", "Trp", "Cys")
> trna <- filter(x, key = "tRNA", product = hydrophobic)
> 
> ## select start, end, orientation, product, and GeneID
> df <- select(trna, "start", "end", "strand", "product", "db_xref.GeneID")
> df
  start   end strand  product db_xref.GeneID
1  9374  9447      1 tRNA-Trp         854581
2 64415 64490      1 tRNA-Cys         854606
3 66095 66179      1 tRNA-Leu         854609
4 70162 70237      1 tRNA-Ile         854618
5 72630 72705      1 tRNA-Met         854621
6 77431 77505      1 tRNA-Phe         854624
7 78533 78608      1 tRNA-Val         854626
8 85035 85112      1 tRNA-Met         854628
> 
> ## combine the above steps into one
> cols <- c("start", "end", "strand", "product", "db_xref.GeneID")
> filter(x, key = "tRNA", product = hydrophobic, .cols = cols)
  start   end strand  product db_xref.GeneID
1  9374  9447      1 tRNA-Trp         854581
2 64415 64490      1 tRNA-Cys         854606
3 66095 66179      1 tRNA-Leu         854609
4 70162 70237      1 tRNA-Ile         854618
5 72630 72705      1 tRNA-Met         854621
6 77431 77505      1 tRNA-Phe         854624
7 78533 78608      1 tRNA-Val         854626
8 85035 85112      1 tRNA-Met         854628
> 
> ## filter all CDS from position 60,000 bp onward
> filter(x, key = "CDS", range = "60000..")
Loading required package: Biostrings
Loading required package: BiocGenerics
Loading required package: parallel

Attaching package: ‘BiocGenerics’

The following objects are masked from ‘package:parallel’:

    clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
    clusterExport, clusterMap, parApply, parCapply, parLapply,
    parLapplyLB, parRapply, parSapply, parSapplyLB

The following object is masked from ‘package:biofiles’:

    strand<-

The following objects are masked from ‘package:stats’:

    IQR, mad, sd, var, xtabs

The following objects are masked from ‘package:base’:

    Filter, Find, Map, Position, Reduce, anyDuplicated, append,
    as.data.frame, basename, cbind, colMeans, colSums, colnames,
    dirname, do.call, duplicated, eval, evalq, get, grep, grepl,
    intersect, is.unsorted, lapply, lengths, mapply, match, mget,
    order, paste, pmax, pmax.int, pmin, pmin.int, rank, rbind,
    rowMeans, rowSums, rownames, sapply, setdiff, sort, table, tapply,
    union, unique, unsplit, which, which.max, which.min

Loading required package: S4Vectors
Loading required package: stats4

Attaching package: ‘S4Vectors’

The following object is masked from ‘package:base’:

    expand.grid

Loading required package: IRanges

Attaching package: ‘IRanges’

The following objects are masked from ‘package:biofiles’:

    ranges, shift

Loading required package: XVector

Attaching package: ‘Biostrings’

The following object is masked from ‘package:base’:

    strsplit

Error in (function (classes, fdef, mtable)  : 
  unable to find an inherited method for function ‘narrow’ for signature ‘"DNAStringSet"’
Calls: <Anonymous> ... <Anonymous> -> <Anonymous> -> narrow -> <Anonymous>
Execution halted