class_docstr: Class for generating a white noise array
code: def __init__(self, duration=10, samplerate=44100):
      super(WhiteNoiseArray, self).__init__(
          duration=duration, samplerate=samplerate
      )
      array = numpy.random.randn(self.num_samples, 1)
      self.array = array / abs(array).max()
  
imports: from __future__ import division
  import gi
  from gi.repository import GLib, Gst
  import numpy
  import scipy.signal.waveforms
  import os.path
  import ffmpeg
label_desc: Use image node_id 1 to create a new WhiteNoiseArray object from inherited base classes: SampleArray with example: obj = WhiteNoiseArray(duration, samplerate)