Clarify append-only semantics and short-lived context lifetimes

[zanate4019]

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Relating to your tip "Entity Framework Core will automatically fix-up navigation properties to any other entities that were previously loaded into the context instance. So even if you don't explicitly include the data for a navigation property, the property may still be populated if some or all of the related entities were previously loaded."

How do I ensure that a query retrieves a navigation property from the database even if it is already loaded into the context instance?