void (@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); } }