def get_managed_field_names(fieldmodule):
    """
    Get names of managed fields in fieldmodule.
    """
    field_names = []
    field_iter = fieldmodule.createFielditerator()
    field = field_iter.next()
    while field.isValid():
        if field.isManaged():
            field_names.append(field.getName())
        field = field_iter.next()
    return field_names