Send LaG/LaGQ command. 
- Parameters
- 
  
    | c | A pointer to yrmcds. |  | key | Key data. |  | key_len | Length of key. |  | quiet | 0 to send LaG, other values to send LaGQ. |  | serial | A pointer to uint32_t, orNULL. |  
 
- Returns
- 0 if succeeded. Other values indicate an error.
This function sends LaG/LaGQ command to the server. If serial is not NULL, the serial number of the request will be stored if the command was sent successfully.