code: public static ObjectMapper init(ObjectMapper mapper, String filter) throws IllegalStateException {
          return init(mapper, new SimpleSquigglyContextProvider(new SquigglyParser(), filter));
      }
docs: Initialize a @{@link SquigglyPropertyFilter} with a static filter expression.
  
  @param mapper the Jackson Object Mapper
  @param filter the filter expressions
  @return object mapper, mainly for convenience
  @throws IllegalStateException if the filter was unable to be registered