public void forEach(BiConsumer<? super K, ? super V> action) {
        requireNonNull(action);
        inner.forEach(e -> action.accept(e.getKey(), e.getValue()));
    }
Performs an action for each key-value pair of this stream.
<p>
This is a terminal operation.
<p>
The behavior of this operation is explicitly nondeterministic.
For parallel stream pipelines, this operation does <em>not</em>
guarantee to respect the encounter order of the stream, as doing so
would sacrifice the benefit of parallelism.  For any given element, the
action may be performed at whatever time and in whatever thread the
library chooses.  If the action accesses shared state, it is
responsible for providing the required synchronization.

@param action a non-interfering action to perform on the key-value pairs
@throws NullPointerException if any of the provided parameters are {@code null}
common-parent/mapstream/src/main/java/com/speedment/common/mapstream/MapStream.java