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Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

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Design pattern: Lazy initialization

Description: Delay creation of a required instance (accessed using a key) until the instance is requested.

This pattern can be used with both classes and prototypes. The description above is from the Wikipedia page on this pattern:

https://en.wikipedia.org/wiki/Lazy_initialization

This pattern is not described in the GoF book. See the Wikipedia page for details and references.

The sample implementation uses classes.