def IsBefore(version, major, minor, revision):
  """Decide if a given version is strictly before a given version.

  @param version: (major, minor, revision) or None, with None being
      before all versions
  @type version: (int, int, int) or None
  @param major: major version
  @type major: int
  @param minor: minor version
  @type minor: int
  @param revision: revision
  @type revision: int

  """
  if version is None:
    return True

  return version < (major, minor, revision)