'Fetch an IP block
:param  ex_href: The href of the IP block.
:type   ex_href: ``str``
:param  ex_ip_block_id: The ID of the IP block.
:type   ex_ip_block_id: ``str``
:return:    Instance class ``ProfitBricksIPBlock``
:rtype:     :class:`ProfitBricksIPBlock`'

def ex_describe_ip_block(self, ex_href=None, ex_ip_block_id=None):

    use_full_url = True
    if (ex_href is None):
        if (ex_ip_block_id is None):
            raise ValueError('The    IP    block    ID    is    required.')
        else:
            use_full_url = False
            ex_href = 'ipblocks/{ip_block_id}'.format(ip_block_id=ex_ip_block_id)
    response = self.connection.request(action=ex_href, params={'depth': 3}, method='GET', with_full_url=use_full_url)
    return self._to_ip_block(response.object)
