XLEN
Syntax
        XLEN key
- Available since:
 - 5.0.0
 - Time complexity:
 - O(1)
 - ACL categories:
 - 
              
                
@read,@stream,@fast, 
Returns the number of entries inside a stream. If the specified key does not
exist the command returns zero, as if the stream was empty.
However note that unlike other Redis types, zero-length streams are
possible, so you should call TYPE or EXISTS in order to check if
a key exists or not.
Streams are not auto-deleted once they have no entries inside (for instance
after an XDEL call), because the stream may have consumer groups
associated with it.