public boolean allMatch(BiPredicate<? super K, ? super V> predicate) {
        requireNonNull(predicate);
        return inner.allMatch(e -> predicate.test(e.getKey(), e.getValue()));
    }
Returns whether all key-value pairs of this stream match the provided 
predicate. May not evaluate the predicate on all key-value pairs if not 
necessary for determining the result. If the stream is empty then 
{@code true} is returned and the predicate is not evaluated.
<p>
This is a short-circuiting terminal operation.

<p>
This method evaluates the <em>universal quantification</em> of the
predicate over the elements of the stream (for all x P(x)).  If the
stream is empty, the quantification is said to be <em>vacuously
satisfied</em> and is always {@code true} (regardless of P(x)).

@param predicate  a non-interfering, stateless predicate to apply to 
                  key-value pairs of this stream
@return           {@code true} if either all key-value pairs of the 
                  stream match the provided predicate or the stream is 
                  empty, otherwise {@code false}
@throws NullPointerException if any of the provided parameters are {@code null}
common-parent/mapstream/src/main/java/com/speedment/common/mapstream/MapStream.java