This is a row of cCell . The sid argument refers to the column either by column name or number. Where sid optional and omitted the complete row is operated on. Where sid is present the the cCell it addresses in the cDataRow is operated on.
cDataRow.Refresh() will refresh the entire row and cDataRow.cell(“London”).Refresh() will refresh a specific cell. cDataRow.refresh() is equivalent to cDataSet.row(“some rowid”).refresh()
You can find the methods and properties documentation on github.