Pass a share handle as a parameter. The share handle must have been
created by a previous call to curl_share_init(3). Setting this option,
will make this curl handle use the data from the shared handle instead of
keeping the data to itself. This enables several curl handles to share
data. If the curl handles are used simultaneously in multiple threads, you
MUST use the locking methods in the share handle. See
curl_share_setopt(3) for details.
If you add a share that is set to share cookies, your easy handle will use
that cookie cache and get the cookie engine enabled. If you unshare an object
that was using cookies (or change to another object that doesnt share
cookies), the easy handle will get its cookie engine disabled.
Data that the share object is not set to share will be dealt with the usual
way, as if no share was used.
Set this option to NULL again to stop using that share object.