Move implementation detail from docstring to comment

Signed-off-by: Gilles Peskine <[email protected]>

tests/scripts/generate_bignum_tests.py

@@ -74,11 +74,9 @@ def quote_str(val) -> str:
     return "\"{}\"".format(val)
 
 def combination_pairs(values: List[T]) -> List[Tuple[T, T]]:
-    """Return all pair combinations from input values.
-
-    The return value is cast, as older versions of mypy are unable to derive
-    the specific type returned by itertools.combinations_with_replacement.
-    """
+    """Return all pair combinations from input values."""
+    # The return value is cast, as older versions of mypy are unable to derive
+    # the specific type returned by itertools.combinations_with_replacement.
     return typing.cast(
         List[Tuple[T, T]],
         list(itertools.combinations_with_replacement(values, 2))