old_contents: from .utils import sha256
  
  
  class Network:
      def __init__(self, network_passphrase: str) -> None:
          self.network_passphrase = network_passphrase
  
      def network_id(self) -> bytes:
          return sha256(self.network_passphrase.encode())
  
      def __eq__(self, other: 'Network') -> bool:
          return self.network_passphrase == other.network_passphrase
  
  
  _network_passphrases = {
      'PUBLIC': 'Public Global Stellar Network ; September 2015',
      'TESTNET': 'Test SDF Network ; September 2015'
  }
  
  PUBLIC = Network(_network_passphrases['PUBLIC'])  # type: Network
  TESTNET = Network(_network_passphrases['TESTNET'])  # type: Network
  
new_contents: from .utils import sha256
  
  
  class Network:
      def __init__(self, network_passphrase: str) -> None:
          self.network_passphrase = network_passphrase
  
      def network_id(self) -> bytes:
          return sha256(self.network_passphrase.encode())
  
      def __eq__(self, other: 'Network') -> bool:
          return self.network_passphrase == other.network_passphrase
  
  
  PUBLIC_NETWORK_PASSPHRASE: str = 'Public Global Stellar Network ; September 2015'
  TESTNET_NETWORK_PASSPHRASE: str = 'Test SDF Network ; September 2015'
  
  PUBLIC: Network = Network(PUBLIC_NETWORK_PASSPHRASE)
  TESTNET: Network = Network(TESTNET_NETWORK_PASSPHRASE)
  
subject: add network passphrase