anchor.diff:   * implements the summary format.
    *
    * The code generation process introduces the following non-typical semantics:
  - * - Fields of type List have a default value of the empty list.
  - * - Fields of type int have a default value of zero.
  - * - Fields of type String have a defauld value of ''.
  + * - Fields of type List are never null, and have a default value of the empty
  + *   list.
  + * - Fields of type int are never null, and have a default value of zero.
  + * - Fields of type String are never null, and have a default value of ''.
    *
    * Terminology used in this document:
    * - "Unlinked" refers to information that can be determined from reading the
  
positive.code:   List<UnlinkedTypeParam> typeParameters;
  
    /**
     * Supertype of the class, or `null` if the class doesn't explicitly declare
     * a supertype.
     */
    UnlinkedTypeRef supertype;
  
  
negative.code:   String name;
  
    /**
     * Values listed in the enum declaration, in declaration order.
     */
    List<UnlinkedEnumValue> values;
  
  