add a base class for jdwp structs

projects/jdwp/runtime/BUCK

@@ -11,6 +11,7 @@ python_library(
   srcs = [
     ":type-aliases",
     "async_streams.py",
+    "jdwpstruct.py",
   ],
   visibility = ["PUBLIC", ],
   deps = [],

projects/jdwp/runtime/jdwpstruct.py

@@ -0,0 +1,20 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+
+from __future__ import annotations
+
+import abc
+from projects.jdwp.runtime.async_streams import (
+    JDWPInputStreamBase,
+    JDWPOutputStreamBase,
+)
+
+
+class JDWPStruct(abc.ABC):
+    @abc.abstractmethod
+    async def serialize(self, output: JDWPOutputStreamBase):
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    async def parse(input: JDWPInputStreamBase) -> JDWPStruct:
+        pass

projects/jdwp/tests/BUCK

@@ -5,6 +5,7 @@ python_test(
   deps = [
     "//projects/jdwp/defs:defs",
     "//projects/jdwp/codegen:codegen",
+    "//projects/jdwp/runtime:runtime",
   ],
   srcs = glob(["**/*.py"]),
 )

projects/jdwp/tests/runtime/jdwpstruct.py

@@ -0,0 +1,8 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+
+import unittest
+
+
+class JDWPStructTest(unittest.TestCase):
+    def test_jdwpstruct_can_be_imported(self):
+        from projects.jdwp.runtime.jdwpstruct import JDWPStruct