code: def is_file(cls, file):
          '''Return whether the file is likely to be HTML.'''
          peeked_data = wpull.string.printable_bytes(
              wpull.util.peek_file(file)).lower()
  
          if b'<!doctype html' in peeked_data \
             or b'<head' in peeked_data \
             or b'<title' in peeked_data \
             or b'<html' in peeked_data \
             or b'<script' in peeked_data \
             or b'<table' in peeked_data \
             or b'<a href' in peeked_data:
              return Truf is_file(cls, file):
          '''Return whether the file is likely to be HTML.'''
          peeked_data = wpull.string.printable_bytes(
              wpull.util.peek_file(file)).lower()
  
          if b'<!doctype html' in peeked_data \
             or b'<head' in peeked_data \
             or b'<title' in peeked_data \
             or b'<html' in peeked_data \
             or b'<script' in peeked_data \
             or b'<table' in peeked_data \
             or b'<a href' in peeked_data:
              return True
docs: Return whether the file is likely to be HTML.