:sig
StringMap memcache_get_multiple(u64 connection, StringList keys)

:params
connection : connection handle
keys : a list of strings containing the keys to be retrieved
return value : a StringMap with the retrieved entries

:see
>memcache

:content
Retrieves multiple entries in one call.

The result is returned as a `StringMap` keyed by the requested Memcache keys.

:example
u64 conn = memcache_connect();
if(conn != 0)
{
    memcache_set(conn, "doc_k1", "v1");
    memcache_set(conn, "doc_k2", "v2");
    StringList keys; keys.push_back("doc_k1"); keys.push_back("doc_k2");
    StringMap vals = memcache_get_multiple(conn, keys);
    print(vals["doc_k1"], " / ", vals["doc_k2"], "\n");
}
else print("(requires a reachable memcached server)\n");