From 80fd76f1f2091929a64aa973880f7795bb33bd0e Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 1 Mar 2023 13:45:32 +0000
Subject: [PATCH] Document TreeDataType

---
 docs/api/tree.md             | 1 +
 src/textual/widgets/_tree.py | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/docs/api/tree.md b/docs/api/tree.md
index 59b715276..2cf2329fa 100644
--- a/docs/api/tree.md
+++ b/docs/api/tree.md
@@ -1,3 +1,4 @@
 ::: textual.widgets.Tree
 ::: textual.widgets._tree.TreeNode
 ::: textual.widgets._tree.NodeID
+::: textual.widgets._tree.TreeDataType
diff --git a/src/textual/widgets/_tree.py b/src/textual/widgets/_tree.py
index 5202b9447..71b7ed2e2 100644
--- a/src/textual/widgets/_tree.py
+++ b/src/textual/widgets/_tree.py
@@ -29,6 +29,8 @@ NodeID = NewType("NodeID", int)
 """The type of an ID applied to a [TreeNode][textual.widgets._tree.TreeNode]."""
 
 TreeDataType = TypeVar("TreeDataType")
+"""The type of the data for a given instance of a [Tree][textual.widgets.Tree]."""
+
 EventTreeDataType = TypeVar("EventTreeDataType")
 
 LineCacheKey: TypeAlias = "tuple[int | tuple, ...]"