input: import numpy as np
  
  def generate_voltage_signal(frequency: int, amplitude: float, noise_level: float, duration: float, num_samples: int) -> np.ndarray:
      """ Generate a voltage signal with random noise.
      >>> np.random.seed(0)
      >>> generate_voltage_signal(250, 1, 0.1, 1, 1000)
      array([ 1.36589321e+00,  6.04464318e-02, -7.00115528e-01, ...,
              9.32547211e-01,  8.61858780e-01, -3.86578435e-02])
      """
      t = np.linspace(0, duration, num_samples)
      voltage_signal = amplitude * np.sin(2 * np.pi * frequency * t) + np.random.normal(0, noise_level, num_samples)
      return voltage_signal
output:     t = np.linspace(0, duration, num_samples)
      voltage_signal = amplitude * np.sin(2 * np.pi * frequency * t) + np.random.normal(0, noise_level, num_samples)
      return voltage_signal