1 2 3 4 five six 7
 key   0:0                       
 num   0:1   ^                   1
pair   0:1   ^                   1
 key   2:2    ^                  
 num   2:3     ^                 2
pair   2:3     ^                 2
 key   4:4      ^                
 num   4:5       ^               3
pair   4:5       ^               3
 key   6:6        ^              
 num   6:7         ^             4
pair   6:7         ^             4
 key  17:17                  ^   
 num  17:18                   ^  7
pair  17:18                   ^  7
msg         :1 2 3 4 five six 7
format      :# # # # five six #
{
    "col_0": 1,
    "col_1": 2,
    "col_2": 3,
    "col_3": 4,
    "col_4": 7
}