old_contents: class TSS(object):
  
      def __init__(self, seq_id, pos, strand, extra=None):
          """A transcription start site
          
          seq_id - identifier of the harboring chromosome, plasmid, etc.
          pos - position of the
          strand - the strand (+ or -)
          extra - any other information that should be associated
  
          There is no assumptions / restrictions if the TSS position is
          in a 0-based or 1-based coordinate system.
          """
  
          self.seq_id = seq_id
          self.pos = int(pos)
          self.strand = strand
          if extra:
              self.extra = extra
  
new_contents: class TSS(object):
  
      def __init__(self, seq_id, pos, strand, extra=None):
          """A transcription start site
          
          seq_id - identifier of the harboring chromosome, plasmid, etc.
          pos - position of the
          strand - the strand (+ or -)
          extra - any other information that should be associated
  
          There is no assumptions / restrictions if the TSS position is
          in a 0-based or 1-based coordinate system.
          """
  
          self.seq_id = seq_id
          self.pos = int(pos)
          self.strand = strand
          if extra:
              self.extra = extra
  
      def __repr__(self):
          extra_str = ""
          if not self.extra is None:
              extra_str = self.extra
          return "TSS: replicon: %s pos: %s strand: %s extra: %s" % (
              self.seq_id, self.pos, self.strand, extra_str)
  
subject: Add __repr__ to TSS