Optional blockingOptional dataUsed for "database" commands to enforce type checking.
Private loggerMaximum number of parameters allowed. -1 for no maximum.
Minimum number of parameters require.
Optional pubUsed when PUB/SUB is in effect.
Optional signSign is used in commands with a compliment command. The only current example is INCR/DECR. Sign is 1 for INCR and -1 for DECR
Optional txUsed in transactions to enqueue a command.
Every command must implement the execute method.
Available since 2.0.0.
DISCARD
Flushes all previously queued commands in a transaction and restores the connection state to normal.
If [WATCH]{public link WatchCommand} was used, DISCARD unwatches all keys watched by the connection.
Return value
Simple string reply: always OK.