Removed dangling PowerSet

Author: lucianopaz

pymc3/model_graph.py

@@ -1,4 +1,3 @@
-import itertools
 from collections import deque
 from typing import Iterator, Optional, MutableSet
 
@@ -14,17 +13,6 @@
 RV = Tensor
 
 
-def powerset(iterable):
-    """All *nonempty* subsets of an iterable.
-
-    From itertools docs.
-
-    powerset([1,2,3]) --> (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)
-    """
-    s = list(iterable)
-    return itertools.chain.from_iterable(itertools.combinations(s, r) for r in range(1, len(s)+1))
-
-
 class ModelGraph:
     def __init__(self, model):
         self.model = model