test: Verify stdole.IPicture.Type property after loading.

This is a direct validation of the `stdole.IPicture` interface's behavior.

Author: junkmd

comtypes/test/test_stream.py

@@ -237,6 +237,9 @@ def test_Clone(self):
 )
 _OleLoadPicture.restype = HRESULT
 
+# Constants for the type of a picture object
+PICTYPE_BITMAP = 1
+
 # Constants for GetDeviceCaps
 LOGPIXELSX = 88  # Logical pixels/inch in X
 LOGPIXELSY = 90  # Logical pixels/inch in Y
@@ -361,6 +364,7 @@ def test_ole_load_picture(self):
                 byref(pic),
             )
             self.assertEqual(hr, hresult.S_OK)
+            self.assertEqual(pic.Type, PICTYPE_BITMAP)
             pstm.RemoteSeek(0, STREAM_SEEK_SET)
             buf, read = pstm.RemoteRead(len(data))
         self.assertEqual(bytes(buf)[:read], data)