func (c *callPageIterator) Next(ctx context.Context) (*CallPage, error) {
	cp := new(CallPage)
	err := c.p.Next(ctx, cp)
	if err != nil {
		return nil, err
	}
	c.p.SetNextPageURI(cp.NextPageURI)
	return cp, nil
}
func (c *callPageIterator) Next(ctx context.Context) (*CallPage, error) {
	cp := new(CallPage)
	err := c.p.Next(ctx, cp)
	if err != nil {
		return nil, err
	}
	c.p.SetNextPageURI(cp.NextPageURI)
	return cp, nil
}
// Next returns the next page of resources. If there are no more resources,
// NoMoreResults is returned.