Adds the given entity to the context underlying the set in the Added state such that it will be inserted into the database when SaveChanges is called.
public TEntity Add (TEntity entity);
abstract member Add : 'Entity -> 'Entity
Public Function Add (entity As TEntity) As TEntity
The entity to add.
Note that entities that are already in the context in some other state will have their state set
to Added. Add is a no-op if the entity is already in the context in the Added state.