Streams generally produce elements lazily and avoid production of excess elements when there are short circuiting operations. However, for less common cases laziness is not possible There is a tradeoff between implementation complexity and laziness.

Problematic cases arise for the following:
1. use of an "escape hatch" iterator or spliterator terminal operation 
2. use of nested flatMap operations

It would be beneficial to add some guidance to the stream package documentation.