public default V orElseGet(final Supplier<? extends V> valueSupplier) {
        return this.isPresent() ? this.value() : valueSupplier.get();
    }
If the value is present, return the value, else generate a value given the {@link Supplier}.

@param valueSupplier The supplier to use to generate a value if the property is not present
@return A value
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/Property.java