Make more TLObject methods private

Even though raw API is somewhat necessary at times,
these methods should remain implementation details.

telethon/types/_core/gzippacked.py

@@ -26,7 +26,7 @@ class GzipPacked(tlobject.TLObject):
 
     def __bytes__(self):
         return struct.pack('<I', GzipPacked.CONSTRUCTOR_ID) + \
-               tlobject.TLObject.serialize_bytes(gzip.compress(self.data))
+               tlobject.TLObject._serialize_bytes(gzip.compress(self.data))
 
     @staticmethod
     def read(reader):
@@ -35,7 +35,7 @@ class GzipPacked(tlobject.TLObject):
         return gzip.decompress(reader.tgread_bytes())
 
     @classmethod
-    def from_reader(cls, reader):
+    def _from_reader(cls, reader):
         return GzipPacked(gzip.decompress(reader.tgread_bytes()))
 
     def to_dict(self):

telethon/types/_core/messagecontainer.py

@@ -33,7 +33,7 @@ class MessageContainer(TLObject):
         }
 
     @classmethod
-    def from_reader(cls, reader):
+    def _from_reader(cls, reader):
         # This assumes that .read_* calls are done in the order they appear
         messages = []
         for _ in range(reader.read_int()):

telethon/types/_core/rpcresult.py

@@ -12,13 +12,13 @@ class RpcResult(TLObject):
         self.error = error
 
     @classmethod
-    def from_reader(cls, reader):
+    def _from_reader(cls, reader):
         msg_id = reader.read_long()
         inner_code = reader.read_int(signed=False)
         if inner_code == _tl.RpcError.CONSTRUCTOR_ID:
-            return RpcResult(msg_id, None, _tl.RpcError.from_reader(reader))
+            return RpcResult(msg_id, None, _tl.RpcError._from_reader(reader))
         if inner_code == GzipPacked.CONSTRUCTOR_ID:
-            return RpcResult(msg_id, GzipPacked.from_reader(reader).data, None)
+            return RpcResult(msg_id, GzipPacked._from_reader(reader).data, None)
 
         reader.seek(-4)
         # This reader.read() will read more than necessary, but it's okay.