docs: def decode_pubkey_hex(pubkey_hex):
      """
      Decode a public key for ecdsa verification
      """
      if not isinstance(pubkey_hex, (str, unicode)):
          raise ValueError("public key is not a string")
  
      pubk = keylib.key_formatting.decompress(str(pubkey_hex))
      assert len(pubk) == 130
  
      pubk_raw = pubk[2:]
      pubk_i = (int(pubk_raw[:64], 16), int(pubk_raw[64:], 16))
      return pubk_i