TS.MRANGE add NOLABELS to reduce returned answer

[gkorland]

No description provided.

[filipecosta90]

@gkorland regarding the return value, and in order to keep compatibility on all clients we should return an empty list in the position of the labels array. Do you agree?

example of command with the default option

TS.MRANGE - + COUNT 5 FILTER measurement=cpu fieldname=usage_user

1) 1) "cpu_usage_user{948008140}"
    2)  1) 1) "hostname"
           2) "host_3"
        2) 1) "region"
           2) "us-west-2"
        3) 1) "datacenter"
           2) "us-west-2b"
        4) 1) "rack"
           2) "12"
        5) 1) "os"
           2) "Ubuntu15.10"
        6) 1) "arch"
           2) "x64"
        7) 1) "team"
           2) "CHI"
        8) 1) "service"
           2) "18"
        9) 1) "service_version"
           2) "1"
       10) 1) "service_environment"
           2) "production"
       11) 1) "measurement"
           2) "cpu"
       12) 1) "fieldname"
           2) "usage_user"
    3) 1) 1) (integer) 1451606400000
          2) "8"
       2) 1) (integer) 1451606410000
          2) "7"
       3) 1) (integer) 1451606420000
          2) "6"
       4) 1) (integer) 1451606430000
          2) "5"
       5) 1) (integer) 1451606440000
          2) "5"

example of command with the NOLABELS option

TS.MRANGE - + COUNT 5 NOLABELS FILTER measurement=cpu fieldname=usage_user

1) 1) "cpu_usage_user{948008140}"
    2) (empty array)
    3) 1) 1) (integer) 1451606400000
          2) "8"
       2) 1) (integer) 1451606410000
          2) "7"
       3) 1) (integer) 1451606420000
          2) "6"
       4) 1) (integer) 1451606430000
          2) "5"
       5) 1) (integer) 1451606440000
          2) "5"

[gkorland]

Agree