':param message_id: A message id to identify the ask
:param order_id: A order id to identify the order this tick represents
:param price: A price that needs to be paid for the ask
:param quantity: The quantity that needs to be sold
:param timeout: A timeout for the ask
:param timestamp: A timestamp for when the ask was created
:param public_key: The public key of the originator of this message
:param signature: A signature of this message
:type message_id: MessageId
:type order_id: OrderId
:type price: Price
:type quantity: Quantity
:type timeout: Timeout
:type timestamp: Timestamp
:type public_key: str
:type signature: str'

def __init__(self, message_id, order_id, price, quantity, timeout, timestamp, public_key=EMPTY_PK, signature=EMPTY_SIG):

    super(Ask, self).__init__(message_id, order_id, price, quantity, timeout, timestamp, True, public_key, signature)
