# File lib/ruby-progressbar/progress.rb, line 47
  def decrement
    if progress == 0
      warn "WARNING: Your progress bar is currently at #{progress} out of #{total} " \
           "and cannot be decremented. In v2.0.0 this will become a " \
           "ProgressBar::InvalidProgressError."
    end

    self.progress -= 1 unless progress == 0
  end