Creates a new workflow and returns location of workflow metadata in a response header.

The ID that will be used for the created workflow. Passing an ID is OPTIONAL.

The step from the above set that the exchange starts on. Passing intialStep is REQUIRED.

An OPTIONAL property that specifies the root controller of the instance, which can be used by systems supporting authorization mechanisms like Authorization Capabilities (ZCAPs), which rely on object capabilities. This value can be used in conjunction with the <code>authorization</code> property to simultaneously allow other authorization mechanisms.