code: func (c Client) GetContacts(params *ContactsParams) (*contactsHolder, error) {
  	holder := contactsHolder{}
  	if err := c.Get("contacts", params, &holder); err != nil {
  		return nil, err
  	}
  	for _, contact := range holder.Contacts {
  		if contact.Contact.Email != "" {
  			holder.Emails = append(holder.Emails, contact.Contact.Email)
  		}
  	}
  	return &holder, nil
  }
docs: // GetContacts gets a users contacts