'Return a dictionary of scopes mapped to this xblock\'s explicitly set fields w/o any conversions'

def partition_xblock_fields_by_scope(self, xblock):

    result = defaultdict(dict)
    for field in xblock.fields.itervalues():
        if field.is_set_on(xblock):
            result[field.scope][field.name] = field.read_from(xblock)
    return result
