import csv file by merging multiple rows for a field in a single row

[scostic]

Hello, I have a csv file that  has the following format

ProductName, StringID,GUID,ServicePlans

A, AID,8f0c5670-4e56-4892-b06d-91c085d7004f,APlanA

,,,APlanB

,,,APLanC

B,BID,113feb6c-3fe4-4440-bddc-54d774bf0318,BPlanA

,,,BPlanB

I want to import the csv in a such way that rows with empty fields in ProductName are merged on the non empty filed field  ServicePlans 

the result will be two rwo events

A, AID,8f0c5670-4e56-4892-b06d-91c085d7004f,APlanA APlanB APlanC

B,BID,113feb6c-3fe4-4440-bddc-54d774bf0318,BPlanA BPlanB

can you provide a help with props.conf