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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def format_error(self, field_name, message, index=None):
 """Override-able hook to format a single error message as an Error object. See: http://jsonapi.org/format/#error-objects """

        pointer = ['/data']

        if index is not None:
            pointer.append(str(index))

        relationship = isinstance(
            self.declared_fields.get(field_name), BaseRelationship,
        )
        if relationship:
            pointer.append('relationships')
        elif field_name != 'id':
            # JSONAPI identifier is a special field that exists above the attribute object.
            pointer.append('attributes')

        pointer.append(self.inflect(field_name))

        if relationship:
            pointer.append('data')

        return {
            'detail': message,
            'source': {
                'pointer': '/'.join(pointer),
            },
        }