anchor.diff:   *
    * Clients may not extend, implement or mix-in this class.
    */
  -abstract class FunctionTypeAliasElement implements FunctionTypedElement {
  +abstract class FunctionTypeAliasElement
  +    implements FunctionTypedElement, TypeDefiningElement {
     /**
      * An empty array of type alias elements.
      */
  
positive.code:    */
    @deprecated
    SourceRange get docRange;
  
    /**
     * Return the element that either physically or logically encloses this
  
negative.code:  *
   * Clients may not extend, implement or mix-in this class.
   */
  abstract class FunctionTypedElement implements TypeParameterizedElement {
    /**
     * Return a list containing all of the parameters defined by this executable
     * element.
  