Package check result: ERROR

Check: examples, Result: ERROR
  Running examples in ‘Rgff-Ex.R’ failed
  The error most likely occurred in:
  
  > base::assign(".ptime", proc.time(), pos = "CheckExEnv")
  > ### Name: plot_features
  > ### Title: Plots or exports an image of the feature tree from a GFF file
  > ### Aliases: plot_features
  > 
  > ### ** Examples
  > 
  > test_gff3<-system.file("extdata", "AthSmall.gff3", package="Rgff")
  > plot_features(test_gff3)
  Error in plot_features(test_gff3) : 
    Package "DiagrammeR" is required for plotting a `data.tree::Node` object. Please install it.
  Execution halted