How to move a contact to another group in google contacts?

Question

Google

Good day to all. Can't move contact in google contacts to another group. Example from documentation:

def add_group_membership(gd_client, contact_url, group_atom_id):
    contact = gd_client.GetContact(contact_url)
    contact.group_membership_info.append(contactsdata.GroupMembershipInfo(href=group_atom_id))
    try:
        updated_contact = gd_client.Update(contact)
        return updated_contact
    except gdataclient.RequestError, e:
        print_exc()
        if e.status == 412:
            pass
    return None

contact_url like https://www.google.com/m8/feeds/contacts/{{email}}...
group_atom_id like https://www.google.com/m8/feeds/groups/{{email}}/ full/6
In response I get:

RequestError: Server responded with: 400, <?xml version="1.0" encoding="UTF-8"?>
<errors xmlns="http://schemas.google.com/g/2005">
 <error>
  <domain>GData</domain>
  <code>invalid</code>
  <internalReason>Group membership information not supported.</internalReason>
 </error>
</errors>

Google, everywhere people ask similar questions using urls like http://www.google.com/m8/feeds/contacts/{{email}}/base , which they are advised to change to https://www.google.com/m8 /feeds/contacts/{{email}}... But I already use the latter.
What could be the problem?