docstr: Alter the Saturation of image
  
  Arguments
  ---------
  value : float
      =-1 : gray
      <0 : colors are more muted
      =0 : image stays the same
      >0 : colors are more pure
      =1 : most saturated
code: def __init__(self, value):
      """
      Alter the Saturation of image
  
      Arguments
      ---------
      value : float
          =-1 : gray
          <0 : colors are more muted
          =0 : image stays the same
          >0 : colors are more pure
          =1 : most saturated
      """
      self.value = max(min(value, 1.0), -1.0)
  
imports: import random
  import torch
  from torchvision.transforms.functional import to_tensor
  import numpy
  from ..utils import th_random_choice
label_desc: Use image node_id 1 to create a new Saturation object  with example: obj = Saturation(value)