Fix typo in TypeVar docstring (#8142)
"can be used do declare" → "can be used to declare"
diff --git a/Lib/typing.py b/Lib/typing.py
index a95eb2e..4899263 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -509,7 +509,7 @@
At runtime, isinstance(x, T) and issubclass(C, T) will raise TypeError.
Type variables defined with covariant=True or contravariant=True
- can be used do declare covariant or contravariant generic types.
+ can be used to declare covariant or contravariant generic types.
See PEP 484 for more details. By default generic types are invariant
in all type variables.