@Override
        public void visitPyBinaryExpression(@NotNull PyBinaryExpression node) {
          super.visitPyBinaryExpression(node);

          if (noneComparison.get() || !node.isOperator(PyNames.IS) && !node.isOperator("isnot")) return;

          final PyExpression lhs = node.getLeftExpression();
          final PyExpression rhs = node.getRightExpression();

          if (isReferenceToParameter(lhs) ^ isReferenceToParameter(rhs) &&
              (lhs != null && context.getType(lhs) instanceof PyNoneType) ^ (rhs != null && context.getType(rhs) instanceof PyNoneType)) {
            noneComparison.set(true);
          }
        }
@Override
        public void visitPyBinaryExpression(@NotNull PyBinaryExpression node)