<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _add_tags(self, tags):
 # type: (List[str]) -> bool """Add a list of tag Args: tags (List[str]):
 list of tags to add Returns: bool: True if all tags added or False if any already present. """

        alltagsadded = True
        for tag in tags:
            if not self._add_tag(tag):
                alltagsadded = False
        return alltagsadded