code: public Sheet importCsv(String file, String sheetName, Integer headerRowIndex, Integer primaryRowIndex) throws SmartsheetException {
          return importFile("sheets/import", file,"text/csv", sheetName, headerRowIndex, primaryRowIndex);
      }
docs: Imports a sheet.
  
  It mirrors to the following Smartsheet REST API method: POST /sheets/import
  
  @param file path to the CSV file
  @param sheetName destination sheet name
  @param headerRowIndex index (0 based) of row to be used for column names
  @param primaryRowIndex index (0 based) of primary column
  @return the created sheet
  @throws IllegalArgumentException if any argument is null or empty string
  @throws InvalidRequestException if there is any problem with the REST API request
  @throws AuthorizationException if there is any problem with  the REST API authorization (access token)
  @throws ResourceNotFoundException if the resource cannot be found
  @throws ServiceUnavailableException if the REST API service is not available (possibly due to rate limiting)
  @throws SmartsheetException if there is any other error during the operation