An internal function for data merging.
This is a function that use to match original data and addin data with identified variable.
One sample that is already divided from the original file.
The "addin" file.
The variable that use to merge.
This function is for internal use only, so no need to export it. It figures out the ID in the "addin" file then merge variables in addin file to the original file. This function is used for further "lapply" porcess.
is single line contains original variables and addin variables.