'Attempt to load definition XML from "discussion" folder in OLX, than parse it and update block fields'

@classmethod
def _apply_metadata_and_policy(cls, block, node, runtime):

    try:
        (definition_xml, _) = cls.load_definition_xml(node, runtime, block.scope_ids.def_id)
    except Exception as err:
        log.info('Exception    %s    when    trying    to    load    definition    xml    for    block    %s    -    assuming    XBlock    export    format', err, block)
        return
    metadata = cls.load_metadata(definition_xml)
    cls.apply_policy(metadata, runtime.get_policy(block.scope_ids.usage_id))
    for (field_name, value) in metadata.iteritems():
        if (field_name in block.fields):
            setattr(block, field_name, value)
