@classmethod
def detect_fields(cls, ds):
    """
        Called once to setup the fields of this type

        It should set the following static variables:
        * parameters: dictionary
           Dictionary containing the variables. The keys should match
           those of `cls.attrs`
        * field_list: list of (ftype, fname)
           The list of the field present in the file
        """
    raise NotImplementedError
