code: def minimize(bed_file):
      
      if not bed_file:
          return bed_file
      else:
          sorted_bed = bt.BedTool(bed_file).cut(range(3)).sort()
          if not sorted_bed.fn.endswith(".bed"):
              return sorted_bed.moveto(sorted_bed.fn + ".bed")
          else:
              return sorted_bed
docs: strip a BED file down to its three necessary columns: chrom start end