1. The input will be in the form of list of strings. The size of that list could be anything from 1 byte to 1TB. Therefore, your solution should be robust enough to handle any size.

2. Task: Search and print the list of words in L1 containing with double letters consecutively.

L1 = [aardvarks, aardwolf, aarrdwolves, aasvogel, aasvogels, abaabaca, abbreviate, abbreviated, abbreviates, abbreviating, abbreviation, abbreviations, dispassionate, dispassions, dispatch, dispatched, faience, faiences, fail, failed, failing, failings, faille, failles, fails, failure, failures, fain, faineant, faineants , fainer , fainest, faint , fainted, fainter, fainters, faintest, fainthearted, rapacious, rapaciously, rapaciousness, rapaciousneesses, rappaacities]