code: @Nonnull
  	public Imports filter() {
  		return new Imports(Sets.newHashSet(Collections2.filter(imports, Predicates.and(IGNORE_JAVA_LANG, IGNORE_UNDEFINED))));
  	}
docs: Filters primitive types, types without a package declaration and duplicates and returns them as new instance of
  {@code Imports}.
  
  @return new instance of {@code Imports}