"read section 9.3 of Wasserman's book"
Just to confirm, is this the topic on Bootstrap? Because there might be a discrepancy on the textbook version (in the version I have, section 9.3 is Bootstrap Confidence Intervals).
we are using the most recent version of Wasserman's book and in there, the Section 9.3 is on Maximum Likelihood. If you use another version, please search for the Maximum Likelihood Section.