code: def default_bitcoind_opts(config_file=None, prefix=False):
      
  
      default_bitcoin_opts = virtualchain.get_bitcoind_config(config_file=config_file)
  
      # drop dict values that are None
      default_bitcoin_opts = {k: v for k, v in default_bitcoin_opts.items() if v is not None}
  
      # strip 'bitcoind_'
      if not prefix:
          default_bitcoin_opts = opt_strip('bitcoind_', default_bitcoin_opts)
  
      return default_bitcoin_opts
docs: Get our default bitcoind options, such as from a config file,
      or from sane defaults