code: def execute_r(prog, quiet):
      
      FNULL = open(os.devnull, 'w') if quiet else None
      try:
          input_proc = subprocess.Popen(["echo", prog], stdout=subprocess.PIPE)
          status = subprocess.call("R --no-save --quiet",
                                   stdin=input_proc.stdout,
                                   stdout=FNULL,
                                   stderr=subprocess.STDOUT,
                                   shell=True) # warning, this is a security problem
          if status != 0:
              raise ValueError("ggplot2 bridge failed for program: {}."
                               " Check for an error".format(prog))
      finally:
          if FNULL is not None:
              FNULL.close()
docs: Run the R code prog an R subprocess
  
      @raises ValueError if the subprocess exits with non-zero status