input: 
  import numpy as np 
  
  def generate_voltage_signal(frequency: float, amplitude: float, time_samples: int, noise_std_dev: float) -> np.ndarray:
      """ Generates a voltage signal with random noise. The signal is a sine wave with the specified frequency and amplitude.
      Random Gaussian noise with the specified standard deviation is added to the signal.
      
      >>> generate_voltage_signal(250, 1, 1000, 0.1)
      array([ 0.857304 ,  0.9863823,  1.0518548, ..., -0.0856837, -0.0805427, -0.288037 ])
      """
      t = np.linspace(0, 1, time_samples)
      voltage_signal = amplitude * np.sin(2 * np.pi * frequency * t) + np.random.normal(0, noise_std_dev, time_samples)
      return voltage_signal
  
output:     t = np.linspace(0, 1, time_samples)
      voltage_signal = amplitude * np.sin(2 * np.pi * frequency * t) + np.random.normal(0, noise_std_dev, time_samples)
      return voltage_signal