'Constructor.
Args:
wrapped_list: The list within the protobuf which we wrap.
type_descriptor: A type descriptor describing the type of the list
elements.
container: The protobuf which contains this repeated field.
Raises:
AttributeError: If parameters are not valid.'

def __init__(self, wrapped_list=None, type_descriptor=None, container=None):

    if (wrapped_list is None):
        self.wrapped_list = []
    elif (wrapped_list.__class__ is RepeatedFieldHelper):
        self.wrapped_list = wrapped_list.wrapped_list
    else:
        self.wrapped_list = wrapped_list
    if (type_descriptor is None):
        raise AttributeError('type_descriptor    not    specified.')
    self.type_descriptor = type_descriptor
    self.container = container
