add reactor core
<version>${mongodb-reactivestreams.version}</version>
</dependency>
+ <dependency>
+ <groupId>io.projectreactor</groupId>
+ <artifactId>reactor-core</artifactId>
+ <version>${projectreactor.version}</version>
+ </dependency>
+
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-test</artifactId>
<spring.version>5.1.0.RELEASE</spring.version>
<mongodb-reactivestreams.version>1.9.2</mongodb-reactivestreams.version>
<projectreactor.version>3.2.0.RELEASE</projectreactor.version>
+
</properties>
</project>
