code: def pad_light(self, values):
          
          while len(values) < 4:
              values.append(0.)
  
          return list(map(float, values))
docs: Accept an array of up to 4 values, and return an array of 4 values.
          If the input array is less than length 4, pad it with zeroes until it
          is length 4. Also ensure each value is a float