docs: def get_bitcoind_config(config_file=None, impl=None):
      """
      Set bitcoind options globally.
      Call this before trying to talk to bitcoind.
      """
  
      loaded = False
  
      bitcoind_server = None
      bitcoind_port = None
      bitcoind_user = None
      bitcoind_passwd = None
      bitcoind_timeout = None
      bitcoind_regtest = None
      bitcoind_p2p_port = None
      bitcoind_spv_path = None
  
      regtest = None
  
      if config_file is not None:
  
          parser = SafeConfigParser()
          parser.read(config_file)
  
          if parser.has_section('bitcoind'):
  
              if parser.has_option('bitcoind', 'server'):
                  bitcoind_server = parser.get('bitcoind', 'server')
  
              if parser.has_option('bitcoind', 'port'):
                  bitcoind_port = int(parser.get('bitcoind', 'port'))
  
              if parser.has_option('bitcoind', 'p2p_port'):
                  bitcoind_p2p_port = int(parser.get('bitcoind', 'p2p_port'))
  
              if parser.has_option('bitcoind', 'user'):
                  bitcoind_user = parser.get('bitcoind', 'user')
  
              if parser.has_option('bitcoind', 'passwd'):
                  bitcoind_passwd = parser.get('bitcoind', 'passwd')
  
              if parser.has_option('bitcoind', 'spv_path'):
                  bitcoind_spv_path = parser.get('bitcoind', 'spv_path')
  
              if parser.has_option('bitcoind', 'regtest'):
                  regtest = parser.get('bitcoind', 'regtest')
              else:
                  regtest = 'no'
  
              if parser.has_option('bitcoind', 'timeout'):
                  bitcoind_timeout = float(parser.get('bitcoind', 'timeout'))
  
              if regtest.lower() in ["yes", "y", "true", "1", "on"]:
                  bitcoind_regtest = True
              else:
                  bitcoind_regtest = False
              
              loaded = True
  
      if not loaded:
  
          bitcoind_server = 'bitcoin.blockstack.com'
          bitcoind_port = 8332
          bitcoind_user = 'blockstack'
          bitcoind_passwd = 'blockstacksystem'
          bitcoind_regtest = False
          bitcoind_timeout = 300
          bitcoind_p2p_port = 8333
          bitcoind_spv_path = os.path.expanduser("~/.virtualchain-spv-headers.dat")
  
      default_bitcoin_opts = {
          "bitcoind_user": bitcoind_user,
          "bitcoind_passwd": bitcoind_passwd,
          "bitcoind_server": bitcoind_server,
          "bitcoind_port": bitcoind_port,
          "bitcoind_timeout": bitcoind_timeout,
          "bitcoind_regtest": bitcoind_regtest,
          "bitcoind_p2p_port": bitcoind_p2p_port,
          "bitcoind_spv_path": bitcoind_spv_path
      }
  
      return default_bitcoin_opts