code: def get_project_urls(project):
      
      urls = []
      with ftputil.FTPHost(sra_host, sra_user, sra_password) as ftp_host:
          download_paths = []
          exp_dir = '/sra/sra-instant/reads/ByStudy/sra/SRP/%s/%s/' \
                  %(project[:6], project)
          ftp_host.chdir(exp_dir)
          run_folders = ftp_host.listdir(ftp_host.curdir)
  
          # compile a list of all files
          for folder in run_folders:
              files = ftp_host.listdir(folder)
              assert len(files) == 1
              for f in files:
                  path = exp_dir + folder + '/' + f
                  urls.append(path)
      return urls
docs: Get the URLs for all runs from a given project.
      
      TODO: docstring