Function create_private_chat 

pub async fn create_private_chat(
    user_id: i64,
    force: bool,
    client_id: i32,
) -> Result<Chat, Error>

Returns an existing chat corresponding to a given user

Arguments

• user_id - User identifier
• force - Pass true to create the chat without a network request. In this case all information about the chat except its type, title and photo can be incorrect
• client_id - The client id to send the request to