From e020aaac646c8206faecaa7ee6b3a89929f8aec9 Mon Sep 17 00:00:00 2001
From: Pedro Bressan <phmbressan@usp.br>
Date: Fri, 3 May 2024 10:31:26 -0300
Subject: [PATCH] MNT: use Union is Fluid dataclass type for Python <3.10
 support.

---
 rocketpy/motors/fluid.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rocketpy/motors/fluid.py b/rocketpy/motors/fluid.py
index 03fee39ea..f3bac956b 100644
--- a/rocketpy/motors/fluid.py
+++ b/rocketpy/motors/fluid.py
@@ -1,4 +1,5 @@
 from dataclasses import dataclass
+from typing import Union
 
 import numpy as np
 
@@ -26,7 +27,7 @@ class Fluid:
     """
 
     name: str
-    density: int | float | str | list | Function
+    density: Union[int, float, str, list, Function]
 
     def __post_init__(self):
         """Post initialization method.