text: from unittest import TestCase
  
  import nexus_keycode.protocols.passthrough_uart as uart
  
  
  class TestPassthroughUart(TestCase):
      def test_passthrough_uart__expected_value_returned(self):
          """ Test standard input into passthrough_uart and check
              output"""
          # 'input_bytes' is actually the 'base key' we are deriving
          # the uart security key from
          input_bytes = b"\x01" * 14 + b"\x43\x51"
          uart_security_key = (
              b"\x12\xe4\x87\x62\x5c\x6b\x88\xf4\x1e\xe4\x0b\x16\xb4\xc9\x84\xf2"
          )
          result = uart.compute_uart_security_key(input_bytes)
          self.assertEqual(result, uart_security_key)
  