code: public VaadinForHeroku withFilterMapping(final FilterMapBuilder... filterMaps){
          checkVarArgsArguments(filterMaps);
          this.filterMaps.addAll(Arrays.asList(filterMaps));
          return self();
      }
docs: Add filter mappings to the server configuration.
  A filter with the same name as the one defined in the mapping should also be defined
  using {@link #withFilterDefinition(FilterDefinitionBuilder...)}
  
  @param filterMaps the filter mapping(s)
  @since 0.3