sent = easy:Send(data$)
data$. This can also contain binary data.
To establish the connection, set
#CURLOPT_CONNECT_ONLY option before calling easy:Perform() or multi:Perform().
easy:Send() will not work on connections that were created without this option.
The call will return -1 if it's not possible to send data right now. In that case, you need to try to send the data again because curl uses non-blocking sockets.
easy:Send() may return -1 if the only data that was sent was for internal SSL processing, and no
other data could be sent.