HGET
Syntax
        HGET key field
- Available since:
- 2.0.0
- Time complexity:
- O(1)
- ACL categories:
- 
              
                @read,@hash,@fast,
Returns the value associated with field in the hash stored at key.
Return
Bulk string reply: the value associated with field, or nil when field is not
present in the hash or key does not exist.