Payment Actor Messages

applyCommands	Applies a list of commands to a Payment
charge	Registers a charge for a given amount. If the payment maps an external payment provider, this message should be called after the charge has been approved by the provider.
completeCapture	Completes pending capture and assigns its amount to credit balance. This can be used to force a capture to complete even if there's no underlying charge. Note that this can cause a payment to get a negative credit amount.
create	Creates a new Payment.
query	Queries the payment from the graph.
refund	Registers a refund for a given amount. If the payment maps an external payment provider, this message should be called after the refund has been approved by the provider.