Get the number of names, optionally counting the expired ones
    Return {'error': ...} on failure

def get_num_names(include_expired=False, proxy=None, hostport=None):
    """
    Get the number of names, optionally counting the expired ones
    Return {'error': ...} on failure
    """
    assert proxy or hostport, 'Need proxy or hostport'
    if proxy is None:
        proxy = connect_hostport(hostport)

    schema = {
        'type': 'object',
        'properties': {
            'count': {
                'type': 'integer',
                'minimum': 0,
            },
        },
        'required': [
            'count',
        ],
    }

    count_schema = json_response_schema(schema)

    resp = {}
    try:
        if include_expired:
            resp = proxy.get_num_names_cumulative()
        else:
            resp = proxy.get_num_names()

        resp = json_validate(count_schema, resp)
        if json_is_error(resp):
            return resp

    except ValidationError as e:
        if BLOCKSTACK_DEBUG:
            log.exception(e)

        resp = {'error': 'Server response did not match expected schema.  You are likely communicating with an out-of-date Blockstack node.', 'http_status': 502}
        return resp

    except socket.timeout:
        log.error("Connection timed out")
        resp = {'error': 'Connection to remote host timed out.', 'http_status': 503}
        return resp

    except socket.error as se:
        log.error("Connection error {}".format(se.errno))
        resp = {'error': 'Connection to remote host failed.', 'http_status': 502}
        return resp

    except Exception as ee:
        if BLOCKSTACK_DEBUG:
            log.exception(ee)

        log.error("Caught exception while connecting to Blockstack node: {}".format(ee))
        resp = {'error': 'Failed to contact Blockstack node.  Try again with `--debug`.', 'http_status': 500}
        return resp

    return resp['count']