docs: def overlay(array1, array2, alpha=0.5):
      """Overlays `array1` onto `array2` with `alpha` blending.
  
      Args:
          array1: The first numpy array.
          array2: The second numpy array.
          alpha: The alpha value of `array1` as overlayed onto `array2`. This value needs to be between [0, 1],
              with 0 being `array2` only to 1 being `array1` only (Default value = 0.5).
  
      Returns:
          The `array1`, overlayed with `array2` using `alpha` blending.
      """
      if alpha < 0. or alpha > 1.:
          raise ValueError("`alpha` needs to be between [0, 1]")
      if array1.shape != array2.shape:
          raise ValueError('`array1` and `array2` must have the same shapes')
  
      return (array1 * alpha + array2 * (1. - alpha)).astype(array1.dtype)