RK-A

In the Library Reference book, there are some cases of KPs which included unwanted words in the past tense. In the generate_candidates function where we are skipping all the cases of bad KPs based on POS tags of the words, we need to add another check for "past tense". The past tense check logic from the "filter_by_past_tense" method can be used here as well.

The conditions are to be implemented as follows:
1. original form of the word should be in Past Tense
2. Stemmed form of the above word should not be in the stemmed header variant

These conditions will help us in discarding:
1) derived enum classes -> enum classes
2) given event loop -> event loop
3) oriented event loop -> event loop

While making sure cases like given below are not eliminated:
1) encoded text -> text encodings
2) statement executed -> statement execution
3) derived key -> key derivation
4) allocated objects -> allocating objects