docs: def create_filter(request, mapped_class, geom_attr, **kwargs):
      """ Create MapFish default filter based on the request params.
  
      Arguments:
  
      request
          the request.
  
      mapped_class
          the SQLAlchemy mapped class.
  
      geom_attr
          the key of the geometry property as defined in the SQLAlchemy
          mapper. If you use ``declarative_base`` this is the name of
          the geometry attribute as defined in the mapped class.
  
      \\**kwargs
          additional arguments passed to ``create_geom_filter()``.
      """
      attr_filter = create_attr_filter(request, mapped_class)
      geom_filter = create_geom_filter(request, mapped_class, geom_attr,
                                       **kwargs)
      if geom_filter is None and attr_filter is None:
          return None
      if geom_filter is None:
          return attr_filter
      if attr_filter is None:
          return geom_filter
      return and_(geom_filter, attr_filter)