How can the elements of graph in Redisgraph store on disk?

Question

I interest in the form of the graph's elements in Redisgraph. I wonder how the elements such as nodes, edges and properties stored. Redis use the key-value formation, so I want to know that what is the key, and what is the value.

I know that the elements of graph are stored in RDB file. So I try to use the rdb-dump-tools to dump the dump.rdb file, but unfortunately failed. I just want to know how do the redisGraph or RedismoduleIO transform the Graph object, store the elements of it into key-value formations.

Key: "edge.TYPE.GRAPH_NAME.EDGE_ID"
Value: {
    "src_node": "source_node_key",
    "dst_node": "destination_node_key",
    "relation_type": "edge_type"
}

Is it the true formation? edge.TYPE.GRAPH_NAME.EDGE_ID represent the key, and the next represent the value? Can somebody prove it?