How to use the fitsio.header.FITSRecord function in fitsio

This will over-write if the key already exists, except
        for COMMENT and HISTORY fields

        parameters
        -----------
        record:
            The record, either a dict or a header card string
            or a FITSRecord or FITSCard
        """
        if (isinstance(record_in, dict) and
                'name' in record_in and 'value' in record_in):
            record = {}
            record.update(record_in)
        else:
            record = FITSRecord(record_in)

        # only append when this name already exists if it is
        # a comment or history field, otherwise simply over-write
        key = record['name']
        if key is not None:
            key = key.upper()

        key_exists = key in self._record_map

        if not key_exists or key in ('COMMENT', 'HISTORY', 'CONTINUE', None):
            # append new record
            self._record_list.append(record)
            index = len(self._record_list)-1
            self._index_map[key] = index
        else:
            # over-write existing

parameters
        ----------
        record: string
            Dict representing a record or a string representing a FITS header
            card
        """

        if isstring(record):
            card = FITSCard(record)
            self.update(card)

            self.verify()

        else:

            if isinstance(record, FITSRecord):
                self.update(record)
            elif isinstance(record, dict):
                if 'name' in record and 'value' in record:
                    self.update(record)

                elif 'card_string' in record:
                    self.set_record(record['card_string'])

                else:
                    raise ValueError('record must have name,value fields '
                                     'or a card_string field')
            else:
                raise ValueError("record must be a string card or "
                                 "dictionary or FITSRecord")

"dictionary or FITSRecord")

    def verify(self):
        """
        make sure name,value exist
        """
        if 'name' not in self:
            raise ValueError("each record must have a 'name' field")
        if 'value' not in self:
            raise ValueError("each record must have a 'value' field")


_BLANK = '       '


class FITSCard(FITSRecord):
    """
    class to represent ordinary FITS cards.

    CONTINUE not supported

    examples
    --------

    # from a card
    card=FITSRecord('test    =                   77 / My comment')
    """
    def __init__(self, card_string):
        self.set_card(card_string)

    def set_card(self, card_string):
        self['card_string'] = card_string