code: def read_version(group):
      
      version = ('0.1' if 'version' not in group.attrs
                 else group.attrs['version'])
  
      # decode from bytes to str if needed
      if isinstance(version, bytes):
          version = version.decode()
  
      if not is_supported_version(version):
          raise IOError('version {} is not supported'.format(version))
  
      return version
docs: Return the h5features version of a given HDF5 `group`.
  
      Look for a 'version' attribute in the `group` and return its
      value. Return '0.1' if the version is not found. Raises an IOError
      if it is not supported.