Add typedspark_schema property to a dataset

tests/_core/test_dataset.py

@@ -83,3 +83,8 @@ def test_inherrited_functions_with_other_dataset(spark: SparkSession):
 
     df_a.join(df_b, A.a.str)
     df_a.unionByName(df_b)
+
+
+def test_schema_property_of_dataset(spark: SparkSession):
+    df = create_empty_dataset(spark, A)
+    assert df.typedspark_schema == A

typedspark/_core/dataset.py

@@ -86,6 +86,11 @@ def _add_schema_metadata(self) -> None:
         for field in self._schema_annotations.get_structtype().fields:
             self.schema[field.name].metadata = field.metadata
 
+    @property
+    def typedspark_schema(self) -> Schema:
+        """Returns the ``Schema`` of the ``DataSet``."""
+        return self._schema_annotations
+
     """The following functions are equivalent to their parents in ``DataFrame``, but since they
     don't affect the ``Schema``, we can add type annotations here. We're omitting docstrings,
     such that the docstring from the parent will appear."""