Is it possible to customize borders for a row conditionally?

[ilko-nikolov]

For example I have

  const rowStyleFunction = row => {
    if (row.day % 7 === 0) {
      return { backgroundColor: 'lightgray' }
    }
    return {}
  }

  return (
    <DataTable
      rowStyle={row => rowStyleFunction(row)}
      ...
    />

And it works. There's a column with day property. If it's dividable by 7, the background for the entire row is light gray.
But instead of changing background color, I want to set the bottom border for the row to be for example 3px solid black.
I'm doing it like this borderBottom: '3px solid black' but it doesn't work.