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 1.0.0.
DBSIZE
Return the number of keys in the currently-selected database.
Return value:
Integer reply