def is_appendable_to(self, group):
        """Returns True if the data can be appended in a given group."""
        # First check only the names
        if not all([k in group for k in self._entries.keys()]):
            return False

        # If names are matching, check the contents
        for k in self._entries.keys():
            if not self._entries[k].is_appendable_to(group):
                return False

        return True
Returns True if the data can be appended in a given group.