[Issue]: When defining validation schema for Neo4JGraphQueryEngine, how do I set the relationships? Also, why are there no properties?

[tyler-suard-parker]

Describe the issue

@Eric-Shang Hello Eric. Thank you for writing a module for Neo4J.
This is what the example looks like:

relations = Literal[
    "FOLLOWS",
    "PROVIDES",
    "APPLIES_TO",
    "DEFINED_AS",
    "ASSIGNED_TO",
    "PART_OF",
    "MANAGES",
    "REQUIRES",
    "ENTITLED_TO",
    "REPORTS_TO",
]

# define which entities can have which relations
validation_schema = {
    "EMPLOYEE": ["FOLLOWS", "APPLIES_TO", "ASSIGNED_TO", "ENTITLED_TO", "REPORTS_TO"],
    "EMPLOYER": ["PROVIDES", "DEFINED_AS", "MANAGES", "REQUIRES"],
    "POLICY": ["APPLIES_TO", "DEFINED_AS", "REQUIRES"],
    "BENEFIT": ["PROVIDES", "ENTITLED_TO"],
    "POSITION": ["DEFINED_AS", "PART_OF", "ASSIGNED_TO"],
    "DEPARTMENT": ["PART_OF", "MANAGES", "REQUIRES"],
    "CONTRACT": ["PROVIDES", "REQUIRES", "APPLIES_TO"],
    "RESPONSIBILITY": ["ASSIGNED_TO", "REQUIRES", "DEFINED_AS"],
} ``` 

If I have a graph with uni-directional connections, how should I note the relationships in the validation schema?
If I have the relationship:
(node1) -- likes -> (node2)
How would I note that in the schema?

Would it be 
"node1":["likes"]
"node2":["likes"]

Or would it just be
"node1":["likes"]
?

Also, it is not clear to me where I should put the properties for each node.  Why are there no properties for the nodes in the example?  Thank you for your help.


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