code: def bounds(self):
          
          bounds = []
          for p in self.params:
              if p.fixed:
                  if p.value >= 0.0:
                      bounds.append([np.nextafter(p.value, 0), p.value])
                  else:
                      bounds.append([p.value, np.nextafter(p.value, 0)])
              else:
                  bounds.append([p.min, p.max])
          return bounds
docs: :return: List of tuples of all bounds on parameters.