DittoMutableDocument

This is used as part of update operations for documents. It provides access to updating a document through a subscript-based API. A subscript operation returns a DittoMutableDocumentPath that you can then use to chain further subscript operations to in order to access nested values in a document. Once you've defined the path to a key in a document that you'd like to update, by using subscripts, then you can use the functionality defined on DittoMutableDocumentPath to perform the desired document update(s). Note that objects of this type should only be used within the scope of the update closure that they are provided in.