Object-Oriented Design for Implementation

https://d2l.ai/chapter_linear-regression/oo-design.html

Please let me know how to solve this error.
#call the full implemented HyperParameters class saved in d2l
class B(d2l.HyperParameters):
def init(self, a, b, c):
self.save_hyperparameters(ignore=[‘c’])
print(‘self.a =’, self.a, ‘self.b =’, self.b)
print(‘There is no self.c =’, not hasattr(self, ‘c’))
b = B(a=1, b=2, c=3)

AttributeError Traceback (most recent call last)
Input In [28], in <cell line: 2>()
1 #call the full implemented HyperParameters class saved in d2l
----> 2 class B(d2l.HyperParameters):
3 def init(self, a, b, c):
4 self.save_hyperparameters(ignore=[‘c’])
AttributeError: module ‘d2l.tensorflow’ has no attribute ‘HyperParameters’