Defines the arguments used to execute a command for an aggregate.

The available options are:

• command - the command to execute, typically a struct (e.g. %OpenBankAccount{...}).

• metadata - a map of key/value pairs containing the metadata to be associated with all events created by the command.

• handler - the module that handles the command. It may be either the aggregate module itself or a separate command handler module.

• function - the name of function, as an atom, that handles the command. The default value is :execute, used to support command dispatch directly to the aggregate module. For command handlers the :handle function is used.

• lifespan - a module implementing the Commanded.Aggregates.AggregateLifespan behaviour to control the aggregate instance process lifespan. The default value, Commanded.Aggregates.DefaultLifespan, keeps the process running indefinitely.