docs: def download_fastqc_reports(self,download_dir):
          """
          Downloads the QC report from the DNAnexus sequencing results project.
      
          Args: 
              download_dir: `str` - The local directory path to download the QC report to.
      
          Returns: 
              `str`. The filepath to the downloaded FASTQC reports folder.
          """
          if not os.path.isdir(download_dir):
              os.makedirs(download_dir)  
          msg = "the FASTQC reports to {download_dir}.".format(download_dir=download_dir)
          debug_logger.debug("Downloading " + msg)
          dxpy.download_folder(project=self.dx_project_id,destdir=download_dir,folder=self.DX_FASTQC_FOLDER,overwrite=True)
          success_logger.info("Downloaded " + msg)
          #rename the downloaded folder to ${download_dir}/FASTQC
          return download_dir