def get_current_head(self):
        current_heads = self.get_heads()
        if len(current_heads) > 1:
            raise util.CommandError('Only a single head is supported. The '
                'script directory has multiple heads (due to branching), which '
                'must be resolved by manually editing the revision files to '
                'form a linear sequence. Run `alembic branches` to see the '
                'divergence(s).')

        if current_heads:
            return current_heads[0]
        else:
            return None
Return the current head revision.
dataset/ETHPy150Open goFrendiAsgard/kokoropy/kokoropy/packages/alembic/script.py/ScriptDirectory.get_current_head