LPUSH key element [element ...]
Time complexity: O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.
Insert all the specified values at the head of the list stored at
key does not exist, it is created as empty list before performing the push
key holds a value that is not a list, an error is returned.
It is possible to push multiple elements using a single command call just
specifying multiple arguments at the end of the command.
Elements are inserted one after the other to the head of the list, from the
leftmost element to the rightmost element.
So for instance the command
LPUSH mylist a b c will result into a list
c as first element,
b as second element and
a as third element.
Integer reply: the length of the list after the push operations.
dragonfly> LPUSH mylist "world"
dragonfly> LPUSH mylist "hello"
dragonfly> LRANGE mylist 0 -1