docs: def _shadow_contents_from_chunks(contents, chunks, block_out_regexes=None):
      """Remove all contents in spellcheckable :chunks: from contents."""
      shadow_contents = [list(l) for l in contents]
      for chunk in chunks:
          char_offset = chunk.column
          line_offset = 0
  
          for index, line in enumerate(chunk.data):
              # Block out entire chunk range from shadow_contents
              for character_in_line in range(0, len(line)):
                  shadow_line = chunk.line + line_offset
                  shadow_char = char_offset + character_in_line
                  shadow_contents[shadow_line][shadow_char] = 0
  
              # Also block out certain regexps from this chunk
              line = filter_nonspellcheckable_tokens(line,
                                                     block_out_regexes)
              chunk.data[index] = line
  
              line_offset += 1
              char_offset = 0
  
      return shadow_contents