def update_defaults(self, new_defaults, respect_none=False):
for key, value in six.iteritems(new_defaults):<EOL><INDENT>item = self.get_item(key)<EOL>if item is None:<EOL><INDENT>raise YapconfItemNotFound("<STR_LIT>"<EOL>"<STR_LIT>"<EOL>"<STR_LIT>".format(key, key), None)<EOL><DEDENT>item.update_default(value, respect_none)<EOL><DEDENT>
Update items defaults to the values in the new_defaults dict.

        Args:
            new_defaults (dict): A key-value pair of new defaults to be
                applied.
            respect_none (bool): Flag to indicate if ``None`` values should
                constitute an update to the default.