code: private static void validateNoOverlaps(List<CodeReplacement> replacements) {
      checkState(ORDER_CODE_REPLACEMENTS.isOrdered(replacements));
      if (containsOverlaps(replacements)) {
        throw new IllegalArgumentException(
            "Found overlap between code replacements!\n" + Joiner.on("\n\n").join(replacements));
      }
    }
docs: Validates that none of the CodeReplacements have any overlap, since applying
  changes that have overlap will produce malformed results.
  The replacements must be provided in order sorted by start position, as sorted
  by ORDER_CODE_REPLACEMENTS.