full_expectation_ doesn't work on predicted triangle

[henrydingliu]

Are you on the latest chainladder version?

• Yes, this bug occurs on the latest version.

Describe the bug in words

the ful_expectation_ property of a predicted triangle erros

How can the bug be reproduced?

tri = cl.load_sample('raa')
dev = cl.Development().fit_transform(tri)
est = cl.Chainladder().fit(dev,sample_weight=None)
pred = est.predict(dev)
print(est.full_expectation_)
print(pred.full_expectation_)

What is the expected behavior?

tri = cl.load_sample('raa')
dev = cl.Development().fit_transform(tri)
est = cl.Chainladder().fit(dev,sample_weight=None)
pred = est.predict(dev)
assert est.full_expectation_ == pred.full_expectation_