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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def unpin_chat_message( self, chat_id: Union[int, str] ) -> bool: """Use this method to unpin a message in a group, channel or your own chat. You must be an administrator in the chat for this to work and must have the "can_pin_messages" admin right in the supergroup or "can_edit_messages" admin right in the channel. Args: chat_id (``int`` | ``str``):
 Unique identifier (int) or username (str) of the target chat. Returns: True on success. Raises: :class:`RPCError <pyrogram.RPCError>` in case of a Telegram RPC error. """

        self.send(
            functions.messages.UpdatePinnedMessage(
                peer=self.resolve_peer(chat_id),
                id=0
            )
        )

        return True