looking closer, whats the reason for the preceding newline?

I think this should work for the method:

```python
outstr = []
for op, crit in zip(self._operators, self._criteria):
    outstr.append(op) # if there are valid instances where this would not be a string, use str(op)
    outstr.append(crit) # if there are valid instances where this would not be a string, use str(crit)
    outstr.append('\n')
return ''.join(outstr)
```