db: Also include import alias in code snippet.

[abhijeetbodas2001]

In chapter 18,

Here, the 2nd code snippet makes a reference to BasicExperiment, which is as yet not mentioned/defined anywhere in the text.

Looking into the code revealed that it is infact an import alias:

from record_original import BasicRec as BasicExperiment

I think it would be better to include this import as well inside the code snippet for clarity.

Also, thanks for all your work on this book! Really enjoying reading it.