diff --git a/koerce/patterns.py b/koerce/patterns.py
index bca61c0..fe4ce58 100644
--- a/koerce/patterns.py
+++ b/koerce/patterns.py
@@ -11,13 +11,12 @@
     ForwardRef,
     Literal,
     Optional,
-    Self,
     TypeVar,
     Union,
 )
 
 import cython
-from typing_extensions import GenericMeta, get_original_bases
+from typing_extensions import GenericMeta, Self, get_original_bases
 
 # TODO(kszucs): would be nice to cimport Signature and Builder
 from .builders import Builder, Deferred, Variable, builder
diff --git a/koerce/tests/test_patterns.py b/koerce/tests/test_patterns.py
index b83e702..a7c63fb 100644
--- a/koerce/tests/test_patterns.py
+++ b/koerce/tests/test_patterns.py
@@ -11,13 +11,13 @@
     List,
     Literal,
     Optional,
-    Self,
     Sequence,
     TypeVar,
     Union,
 )
 
 import pytest
+from typing_extensions import Self
 
 from koerce.builders import Call, Deferred, Variable
 from koerce.patterns import (
diff --git a/koerce/tests/test_utils.py b/koerce/tests/test_utils.py
index 41f43c8..a09635d 100644
--- a/koerce/tests/test_utils.py
+++ b/koerce/tests/test_utils.py
@@ -1,9 +1,10 @@
 from __future__ import annotations
 
 import inspect
-from typing import Dict, Generic, List, Optional, Self, TypeVar, Union
+from typing import Dict, Generic, List, Optional, TypeVar, Union
 
 import pytest
+from typing_extensions import Self
 
 from koerce.utils import (
     get_type_boundvars,
diff --git a/koerce/tests/test_y.py b/koerce/tests/test_y.py
new file mode 100644
index 0000000..e2f0227
--- /dev/null
+++ b/koerce/tests/test_y.py
@@ -0,0 +1,133 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from inspect import Signature as InspectSignature
+from typing import Generic
+
+import ibis
+from coercer import NoMatch, dict_of, instance_of
+from pydantic_core import SchemaValidator
+from typing_extensions import TypeVar
+
+from koerce.patterns import InstanceOf, ObjectOf, ObjectOfN, PatternMap
+from koerce.utils import Signature
+
+T = TypeVar("T")
+S = TypeVar("S")
+U = TypeVar("U")
+
+
+class A(Generic[T, S, U]):
+    a: int
+    b: str
+
+    t: T
+    s: S
+
+    @property
+    def u(self) -> U:  # type: ignore
+        ...
+
+
+@dataclass
+class Person:
+    name: str
+    age: int
+    is_developer: bool = True
+    has_children: bool = False
+
+
+v = SchemaValidator(
+    {
+        "type": "typed-dict",
+        "fields": {
+            "name": {
+                "type": "typed-dict-field",
+                "schema": {
+                    "type": "str",
+                },
+            },
+            "age": {
+                "type": "typed-dict-field",
+                "schema": {
+                    "type": "int",
+                },
+            },
+            "is_developer": {
+                "type": "typed-dict-field",
+                "schema": {
+                    "type": "bool",
+                },
+            },
+            "has_children": {
+                "type": "typed-dict-field",
+                "schema": {
+                    "type": "bool",
+                },
+            },
+        },
+    }
+)
+
+p = Person(name="Samuel", age=35, is_developer=True, has_children=False)
+
+# V = dict_of({"name": str, "age": int, "is_developer": bool})
+
+data = {"name": "Samuel", "age": 35, "is_developer": True, "has_children": False}
+
+
+ITS = 10
+
+
+# def test_pydantic(benchmark):
+#     r1 = benchmark.pedantic(
+#         v.validate_python, args=(data,), iterations=ITS, rounds=20000
+#     )
+#     assert r1 == data
+
+
+# def test_koerce(benchmark):
+#     pat = PatternMap(
+#         {"name": str, "age": int, "is_developer": bool, "has_children": bool}
+#     )
+#     r2 = benchmark.pedantic(pat.apply, args=(data, {}), iterations=ITS, rounds=20000)
+#     assert r2 == data
+
+
+# def test_coercer(benchmark):
+#     pat = dict_of({"name": str, "age": int, "is_developer": bool, "has_children": bool})
+#     r2 = benchmark.pedantic(pat.apply, args=(data, {}), iterations=ITS, rounds=20000)
+#     assert r2 == data
+
+
+########################################
+
+
+# def test_instance_of():
+#     pattern = instance_of(int)
+#     assert pattern.apply(1) == 1
+#     assert pattern.apply(4.0) is NoMatch
+
+
+def func(x: int, y: str, *args: int, z: float = 3.14, **kwargs) -> float: ...
+
+
+args = (1, "a", 2, 3, 4)
+kwargs = dict(z=3.14, w=5, q=6)
+expected = {"x": 1, "y": "a", "args": (2, 3, 4), "z": 3.14, "kwargs": {"w": 5, "q": 6}}
+
+
+def test_inspect(benchmark):
+    sig = InspectSignature.from_callable(func)
+    r = benchmark.pedantic(
+        sig.bind, args=args, kwargs=kwargs, iterations=ITS, rounds=20000
+    )
+    assert r.arguments == expected
+
+
+def test_signature(benchmark):
+    sig = Signature.from_callable(func)
+    r = benchmark.pedantic(
+        sig.bind, args=args, kwargs=kwargs, iterations=ITS, rounds=20000
+    )
+    assert r == expected