old_contents: from pycoin.networks.bitcoinish import create_bitcoinish_network
  
  from pycoin.coins.bgold.Tx import Tx as BgoldTx
  from pycoin.coins.bgold.Block import Block as BgoldBlock
  
  # fork at block 491407
  
  network = create_bitcoinish_network(
      symbol="BTG", network_name="Bgold", subnet_name="mainnet", tx=BgoldTx, block=BgoldBlock,
      wif_prefix_hex="80", sec_prefix="BTCSEC:", address_prefix_hex="26", pay_to_script_prefix_hex="17",
      bip32_prv_prefix_hex="0488ade4", bip32_pub_prefix_hex="0488B21E",
      magic_header_hex="e1476d44", default_port=8338,
      dns_bootstrap=[
          "eu-dnsseed.bitcoingold-official.org", "dnsseed.bitcoingold.org",
          "dnsseed.btcgpu.org",
      ])
  
new_contents: from pycoin.networks.bitcoinish import create_bitcoinish_network
  
  from pycoin.coins.bgold.Tx import Tx as BgoldTx
  from pycoin.coins.bgold.Block import Block as BgoldBlock
  
  # fork at block 491407
  
  network = create_bitcoinish_network(
      symbol="BTG", network_name="Bgold", subnet_name="mainnet", tx=BgoldTx, block=BgoldBlock,
      wif_prefix_hex="80", sec_prefix="BTGSEC:", address_prefix_hex="26", pay_to_script_prefix_hex="17",
      bip32_prv_prefix_hex="0488ade4", bip32_pub_prefix_hex="0488B21E",
      magic_header_hex="e1476d44", default_port=8338,
      dns_bootstrap=[
          "eu-dnsseed.bitcoingold-official.org", "dnsseed.bitcoingold.org",
          "dnsseed.btcgpu.org",
      ])
  
subject: Tweak BTG SEC prefix.