public default Set<MemoryComputeKey> getMemoryComputeKeys() {
        return Collections.emptySet();
    }
The {@link Memory} keys that will be used during the computation.
These are the only keys that can be read or written throughout the life of the {@link GraphComputer}.
The default is an empty set.

@return the set of memory keys that will be read/written
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/VertexProgram.java