Major Description
As described in the PR https://github.com/apache/tinkerpop/pull/2025
Currently all steps that can change graph data implements Mutating interface. However, there is no straight forward way to know whether the step can perform write or delete or both on the graph data. This PR introduces two new marker interfaces Writing and Deleting defining whether step can perform write or delete or both.
In addition to this, this PR creates a static map of Traversal steps that shall be added for a given operator. Both can be combined to assess whether a given query can perform read or write or delete or any combination of these before query execution.
For details see dev list post: https://lists.apache.org/thread/433bc2qr5owvjcfn0tbj55sgz95zg6df