input: Write a function to generate a voltage signal with random noise using a Python script. The function should take the frequency and amplitude of the signal as input parameters and return the voltage signal. Use numpy for generating the signal. If the input frequency or amplitude is not provided, default values of 250 Hz and 1 V respectively should be used.
  assert np.array_equal(generate_voltage_signal(250, 1)[:5], np.sin(2*np.pi*250*np.linspace(0, 1, 1000))[:5] + np.random.normal(0, 0.1, 1000)[:5])==True
  assert np.array_equal(generate_voltage_signal()[:5], np.sin(2*np.pi*250*np.linspace(0, 1, 1000))[:5] + np.random.normal(0, 0.1, 1000)[:5])==True
  assert np.array_equal(generate_voltage_signal(100, 2)[:5], np.sin(2*np.pi*100*np.linspace(0, 1, 1000))[:5] + np.random.normal(0, 0.1, 1000)[:5])==True
output: def generate_voltage_signal(frequency=250, amplitude=1):
      t = np.linspace(0, 1, 1000)
      signal = amplitude * np.sin(2 * np.pi * frequency * t)
      noise = np.random.normal(0, 0.1, 1000)
      return signal + noise