old_contents: 
  from pycoin.serialize import h2b
  
  from pycoin.coins.bitcoin.ScriptTools import BitcoinScriptTools
  from .Tx import Tx as BGoldTx
  from ..bitcoin.extras import Extras
  from pycoin.block import Block as BGoldBlock
  
  from pycoin.ecdsa.secp256k1 import secp256k1_generator
  from pycoin.networks.network import Network
  from pycoin.ui.uiclass import UI
  from pycoin.vm.ScriptInfo import ScriptInfo
  
  # BRAIN DAMAGE
  _script_info = ScriptInfo(BitcoinScriptTools)
  
  # BRAIN DAMAGE
  mainnet_ui = UI(
      _script_info, secp256k1_generator,
      bip32_prv_prefix=h2b("0488ade4"), bip32_pub_prefix=h2b("0488B21E"),
      wif_prefix=h2b("80"), sec_prefix="BTCSEC:", address_prefix=h2b("26"),
      pay_to_script_prefix=h2b("17"), bech32_hrp='bc')
  
  mainnet_extras = Extras(BitcoinScriptTools, mainnet_ui)
  
  BGoldMainnet = Network(
      'BTG', "BGold", "mainnet",
      BGoldTx, BGoldBlock,
      h2b('e1476d44'), 8338, [
          "eu-dnsseed.bitcoingold-official.org", "dnsseed.bitcoingold.org",
          "dnsseed.btcgpu.org",
      ],
      ui=mainnet_ui, extras=mainnet_extras
  )
  
  testnet_ui = UI(
      _script_info, secp256k1_generator,
      bip32_prv_prefix=h2b("04358394"), bip32_pub_prefix=h2b("043587CF"),
      wif_prefix=h2b("ef"), sec_prefix="XTNSEC:", address_prefix=h2b("6f"),
      pay_to_script_prefix=h2b("c4"), bech32_hrp='tb')
  
  testnet_extras = Extras(BitcoinScriptTools, testnet_ui)
  
  BGoldTestnet = Network(
      "XTG", "BGold", "testnet3",
      BGoldTx, BGoldBlock,
      h2b('e1476d44'), 18333, [
          "eu-test-dnsseed.bitcoingold-official.org", "test-dnsseed.bitcoingold.org",
          "test-dnsseed.btcgpu.org", "btg.dnsseed.minertopia.org"
      ],
      ui=testnet_ui, extras=testnet_extras
  )
  
new_contents: 
  from pycoin.serialize import h2b
  
  from pycoin.coins.bitcoin.ScriptTools import BitcoinScriptTools
  from .Tx import Tx as BGoldTx
  from ..bitcoin.extras import Extras
  from pycoin.block import Block as BGoldBlock
  
  from pycoin.ecdsa.secp256k1 import secp256k1_generator
  from pycoin.networks.network import Network
  from pycoin.ui.uiclass import UI
  from pycoin.vm.ScriptInfo import ScriptInfo
  
  # BRAIN DAMAGE
  _script_info = ScriptInfo(BitcoinScriptTools)
  
  # BRAIN DAMAGE
  mainnet_ui = UI(
      _script_info, secp256k1_generator,
      bip32_prv_prefix=h2b("0488ade4"), bip32_pub_prefix=h2b("0488B21E"),
      wif_prefix=h2b("80"), sec_prefix="BTCSEC:", address_prefix=h2b("26"),
      pay_to_script_prefix=h2b("17"), bech32_hrp='bc')
  
  mainnet_extras = Extras(BitcoinScriptTools, mainnet_ui)
  
  # fork at block 491407
  BGoldMainnet = Network(
      'BTG', "BGold", "mainnet",
      BGoldTx, BGoldBlock,
      h2b('e1476d44'), 8338, [
          "eu-dnsseed.bitcoingold-official.org", "dnsseed.bitcoingold.org",
          "dnsseed.btcgpu.org",
      ],
      ui=mainnet_ui, extras=mainnet_extras
  )
  
  testnet_ui = UI(
      _script_info, secp256k1_generator,
      bip32_prv_prefix=h2b("04358394"), bip32_pub_prefix=h2b("043587CF"),
      wif_prefix=h2b("ef"), sec_prefix="XTNSEC:", address_prefix=h2b("6f"),
      pay_to_script_prefix=h2b("c4"), bech32_hrp='tb')
  
  testnet_extras = Extras(BitcoinScriptTools, testnet_ui)
  
  BGoldTestnet = Network(
      "XTG", "BGold", "testnet3",
      BGoldTx, BGoldBlock,
      h2b('e1476d44'), 18333, [
          "eu-test-dnsseed.bitcoingold-official.org", "test-dnsseed.bitcoingold.org",
          "test-dnsseed.btcgpu.org", "btg.dnsseed.minertopia.org"
      ],
      ui=testnet_ui, extras=testnet_extras
  )
  
subject: Add BTG fork comment.