def delete_instance(credentials, project, zone, name, wait_until_done=False):
access_token = credentials.get_access_token()<EOL>headers = {<EOL>'<STR_LIT>': '<STR_LIT>' % access_token.access_token<EOL>}<EOL>r = requests.delete('<STR_LIT>'<EOL>'<STR_LIT>'<EOL>% (project, zone, name),<EOL>headers=headers)<EOL>r.raise_for_status()<EOL>op_name = r.json()['<STR_LIT:name>']<EOL>_LOGGER.info('<STR_LIT>'<EOL>'<STR_LIT>',<EOL>r.status_code)<EOL>if wait_until_done:<EOL><INDENT>_LOGGER.info('<STR_LIT>')<EOL>wait_for_zone_op(access_token, project, zone, op_name)<EOL><DEDENT>return op_name<EOL>
Delete an instance.

    TODO: docstring