docs: def _clean_header(self, header):
          """Remove ISA-Tab specific information from Header[real name] headers.
          """
          if header.find("[") >= 0:
              header = header.replace("]", "").split("[")[-1]
          # ISATab can start with numbers but this is not supported in
          # the python datastructure, so prefix with isa_ to make legal
          try:
              int(header[0])
              header = "isa_" + header
          except ValueError:
              pass
          return header