makeSwitchCaseBody(isEmpty, isDefault) {
    const context = this.switchContext;

    if (!context.hasCase) {
      return;
    }

    /*
     * Merge forks.
     * The parent fork context has two segments.
     * Those are from the current case and the body of the previous case.
     */
    const parentForkContext = this.forkContext;
    const forkContext = this.pushForkContext();

    forkContext.add(parentForkContext.makeNext(0, -1));

    /*
     * Save `default` chunk info.
     * If the `default` label is not at the last, we must make a path from
     * the last `case` to the `default` chunk.
     */
    if (isDefault) {
      context.defaultSegments = parentForkContext.head;
      if (isEmpty) {
        context.foundDefault = true;
      } else {
        context.defaultBodySegments = forkContext.head;
      }
    } else {
      if (!isEmpty && context.foundDefault) {
        context.foundDefault = false;
        context.defaultBodySegments = forkContext.head;
      }
    }

    context.lastIsDefault = isDefault;
    context.countForks += 1;
  }
Makes a code path segment for a `SwitchCase` node.
@param {boolean} isEmpty `true` if the body is empty.
@param {boolean} isDefault `true` if the body is the default case.
@returns {void}