six.iteritems for python 2to3

"""

six.iteritems(dictionary, **kwargs)

    Returns an iterator over dictionary‘s items. This replaces dictionary.iteritems() on Python 2 and dictionary.items() on Python 3. kwargs are passed through to the underlying method.
"""
```
  File "\pyjs\pyjs\options.py", line 78, in __init__
    for n, g in Groups.__dict__.iteritems():
AttributeError: 'mappingproxy' object has no attribute 'iteritems'
```