old_contents: import binascii
  import sys
  
  from cert_schema import Chain, UnknownChainError
  
  unhexlify = binascii.unhexlify
  hexlify = binascii.hexlify
  if sys.version > '3':
      unhexlify = lambda h: binascii.unhexlify(h.encode('utf8'))
      hexlify = lambda b: binascii.hexlify(b).decode('utf8')
  
  
  def obfuscate_email_display(email):
      """Partially hides email before displaying"""
      hidden_email_parts = email.split("@")
      hidden_email = hidden_email_parts[0][:2] + ("*" * (len(hidden_email_parts[0]) - 2)) + "@" + hidden_email_parts[1]
      return hidden_email
  
  
  def get_tx_lookup_chain(chain, txid):
      if chain == Chain.testnet:
          return 'https://tbtc.blockr.io/tx/info/' + txid
      elif chain == Chain.mainnet:
          return 'https://blockchain.info/tx/' + txid
      elif chain == Chain.regtest or chain == Chain.mocknet:
          return 'This has not been issued on a blockchain and is for testing only'
      else:
          raise UnknownChainError(
              'unsupported chain (%s) requested with blockcypher collector. Currently only testnet and mainnet are supported' % chain)
  
new_contents: import binascii
  import sys
  
  from cert_schema import Chain, UnknownChainError
  
  unhexlify = binascii.unhexlify
  hexlify = binascii.hexlify
  if sys.version > '3':
      unhexlify = lambda h: binascii.unhexlify(h.encode('utf8'))
      hexlify = lambda b: binascii.hexlify(b).decode('utf8')
  
  
  def obfuscate_email_display(email):
      """Partially hides email before displaying"""
      hidden_email_parts = email.split("@")
      hidden_email = hidden_email_parts[0][:2] + ("*" * (len(hidden_email_parts[0]) - 2)) + "@" + hidden_email_parts[1]
      return hidden_email
  
  
  def get_tx_lookup_chain(chain, txid):
      if chain == Chain.testnet:
          return 'https://live.blockcypher.com/btc-testnet/tx/' + txid
      elif chain == Chain.mainnet:
          return 'https://blockchain.info/tx/' + txid
      elif chain == Chain.regtest or chain == Chain.mocknet:
          return 'This has not been issued on a blockchain and is for testing only'
      else:
          raise UnknownChainError(
              'unsupported chain (%s) requested with blockcypher collector. Currently only testnet and mainnet are supported' % chain)
  
subject: Update helpers.py for new testnet URL (#67)