input: Write a function to generate a voltage signal with random noise using Python. The function should take the frequency and amplitude of the signal as input and return the generated voltage signal.
  
  def generate_voltage_signal(freq: float, amplitude: float) -> np.ndarray:
      t = np.linspace(0, 1, 1000)
      voltage_signal = amplitude * np.sin(2 * np.pi * freq * t) + np.random.normal(0, 0.1, 1000)
      return voltage_signal
  
  assert np.array_equal(generate_voltage_signal(250, 1).shape, (1000,))
  assert np.isclose(np.mean(generate_voltage_signal(250, 1)), 0, atol=0.1)
  assert np.std(generate_voltage_signal(250, 1)) > 0.05
output: def generate_voltage_signal(freq: float, amplitude: float) -> np.ndarray:
      t = np.linspace(0, 1, 1000)
      voltage_signal = amplitude * np.sin(2 * np.pi * freq * t) + np.random.normal(0, 0.1, 1000)
      return voltage_signal