SETNX works exactly like {@link #set(const(ubyte)[], const(ubyte)[]) SET} with the only difference that if the
key already exists no operation is performed. SETNX actually means "SET if Not eXists".
<p>
Time complexity: O(1)
@param key
@param value
@return Integer reply, specifically: 1 if the key was set 0 if the key was not set
SETNX works exactly like {@link #set(const(ubyte)[], const(ubyte)[]) SET} with the only difference that if the key already exists no operation is performed. SETNX actually means "SET if Not eXists". <p> Time complexity: O(1) @param key @param value @return Integer reply, specifically: 1 if the key was set 0 if the key was not set