Excel file creation step: empty table cells look like empty strings instead of null values

[ValeriAgap21]

When using the step:

When I create temporary excel file containing sheet with name `sheetName` and content:content 
|ColumnA|ColumnB|ColumnC|
|               |value1    |               |
|value2    |               |value3     |
and put its path to STEP variable `variableName`

it looks like all empty cells (between | |) in the generated Excel file are written as empty strings ("") rather than truly empty (null) values.
This causes problems when loading such files into the API, as it results in validation errors for some fields (such as dates).