TypeToken.java 文件源码

@Override
protected Set<TypeToken<? super T>> delegate() {
  ImmutableSet<TypeToken<? super T>> filteredTypes = types;
  if (filteredTypes == null) {
    // Java has no way to express ? super T when we parameterize TypeToken vs. Class.
    @SuppressWarnings({"unchecked", "rawtypes"})
    ImmutableList<TypeToken<? super T>> collectedTypes =
        (ImmutableList) TypeCollector.FOR_GENERIC_TYPE.collectTypes(TypeToken.this);
    return (types =
        FluentIterable.from(collectedTypes)
            .filter(TypeFilter.IGNORE_TYPE_VARIABLE_OR_WILDCARD)
            .toSet());
  } else {
    return filteredTypes;
  }
}