Required. Specifies the path to the data file, relative to the workspace root, that contains the data values for this series. The contents of this file depend on the series type selected below. Multiple files can be specified using wildcard "*.csv" or comma-separated "file1.csv, file2.csv" when the series type is csv. Other series types will match only the first file matching a wildcard pattern. Please see the series type for specific information on the contents.