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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 get_fields(self):
 """ Convert default field names for this sub-serializer into versions where the field name has the prefix removed, but each field object knows the real model field name by setting the field's `source` attribute. """

        prefix = getattr(self.Meta, 'source_prefix', '')
        fields = super(ModelSubSerializer, self).get_fields()
        fields_without_prefix = OrderedDict()
        for field_name, field in fields.items():
            if field_name.startswith(prefix):
                # Set real model field name as field's `source` unless the
                # source is already explicitly set, in which case it is
                # probably a method name not the direct field name
                if not field.source:
                    field.source = field_name
                field_name = field_name[len(prefix):]
            fields_without_prefix[field_name] = field
        return fields_without_prefix