private Map<String, ExecutableElement> noArgMethodsOf(TypeElement type) {
    return methodsOf(type, 0);
  }
The method to copy another collection into this builder. It is {@code addAll} for
one-dimensional collections like {@code ImmutableList} and {@code ImmutableSet}, and it is
{@code putAll} for two-dimensional collections like {@code ImmutableMap} and {@code
ImmutableTable}.
value/src/main/java/com/google/auto/value/processor/PropertyBuilderClassifier.java