Passing arguments to python-wialon API functions

from wialon.api import Wialon, WialonError
from wialon import flags

try:
    wialon_api = Wialon()
    result = wialon_api.token_login(token='YOUR_TOKEN')
    wialon_api.sid = result['eid']

    result = wialon_api.avl_evts()

    print result

    spec = {
        'itemsType': 'avl_unit',
        'propName': 'sys_name',
        'propValueMask': '*',
        'sortType': 'sys_name'
    }

    interval = {"from": 0, "to": 0}

    try:
        units = wialon_api.core_search_items(spec=spec, force=1, flags=flags.ITEM_DATAFLAG_BASE, **interval)
        print units
    except WialonError as e:
        print e


    wialon_api.core_logout()
except WialonError as e:
    pass