findinstances

Documentation for the findinstances command.

Two syntactical exceptions are:

    * The # character is required when a keypath contains an NSPredicate
      keyword. See #size in the examples above.

    * The @ character is used for keypaths on collections to indicate the
      keypath applies to the collection itself, not its items. By default,
      keypaths on collections are applied to their elents. For example,
      using a `count` keypath on an array will result in an array with the
      count value of each item of the origianl array ([T] -> [Int]).
      Instead, using a `@count` keypath will result in the count of the
      array ([T] -> Int).