input: 
  import numpy as np
  
  
  def generate_noisy_signal(frequency: float, amplitude: float, noise_std: float, duration: float, sampling_rate: int) -> np.ndarray:
      """ Generate a voltage signal with random noise based on the given frequency, 
      amplitude, noise standard deviation, duration, and sampling rate.
      >>> generate_noisy_signal(250.0, 1.0, 0.1, 1.0, 1000)
      array([...])  # The output array will contain the noisy signal.
      """
  
output:     t = np.linspace(0, duration, int(sampling_rate * duration), endpoint=False)
      signal = amplitude * np.sin(2 * np.pi * frequency * t)
      noise = np.random.normal(0, noise_std, signal.shape)
      noisy_signal = signal + noise
      return noisy_signal