input: def generate_voltage_signal(frequency: float, amplitude: float) -> np.ndarray:
      """ Generates a voltage signal with random noise given a frequency and amplitude.
      >>> generate_voltage_signal(250, 1)
      array([...] # 1000 random values with the shape of a sinusoidal wave plus noise)
      """
      t = np.linspace(0, 1, 1000)
      voltage_signal = amplitude * np.sin(2 * np.pi * frequency * t) + np.random.normal(0, 0.1, 1000)
      return voltage_signal
output:     t = np.linspace(0, 1, 1000)
      voltage_signal = amplitude * np.sin(2 * np.pi * frequency * t) + np.random.normal(0, 0.1, 1000)
      return voltage_signal