code: def iter_filters_in(target):
      # type: (Any) -> Generator[Tuple[Text, Type[BaseFilter]]]
      
      global legacy_warned
      if not legacy_warned:
          # Set the global flag to ``True`` first, in case the user has
          # ``simplefilter('error')`` set.
          legacy_warned = True
  
          warn(
              'Legacy extension loader is deprecated and will be removed in '
                  'Filters v1.4.  '
                  'See http://filters.readthedocs.io/en/latest/extensions.html#legacy-extensions-loader '
                  'for more information.',
  
              DeprecationWarning,
          )
  
      ift_result = is_filter_type(target)
  
      if ift_result is True:
          logger.debug(
              'Registering extension filter '
              '{cls.__module__}.{cls.__name__}.'.format(
                  cls = target,
              ),
          )
  
          yield target.__name__, target
      elif is_module(target):
          for member_name, member in get_members(target):
              member_ift_result = is_filter_type(member)
  
              if member_ift_result is True:
                  logger.debug(
                      'Registering extension filter '
                      '{cls.__module__}.{cls.__name__}.'.format(
                          cls = member,
                      ),
                  )
  
                  yield member.__name__, member
              else:
                  logger.debug(
                      'Ignoring {module}.{name} ({reason})'.format(
                          module  = target.__name__,
                          name    = member_name,
                          reason  = member_ift_result,
                      ),
                  )
      elif is_class(target):
          logger.debug(
              'Ignoring {cls.__module__}.{cls.__name__} ({reason}).'.format(
                  cls     = target,
                  reason  = ift_result,
              ),
          )
      else:
          logger.debug(
              'Ignoring {target!r} ({reason}).'.format(
                  reason  = ift_result,
                  target  = target,
              ),
          )
docs: Iterates over all filters in the specified module/class.