This might close all connections this handle has used and possibly has kept open until now - unless it was attached to a multi handle while doing the transfers. Don't call this function if you intend to transfer more files, re-using handles is a key to good performance with libcurl.
Occasionally you may get your progress callback or header callback called from within
easy:Close() (if previously set for the
handle using easy:SetOpt()). Like if libcurl decides to shut down the connection and the protocol is of a kind that requires
a command/response sequence before disconnect. Examples of such protocols are FTP, POP3 and IMAP.
Any use of the handle after this function has been called and have returned, is illegal.
easy:Close() kills the handle and all
memory associated with it!