Presto 聚合函数（UDAF） 开发详细步骤

1.加入相关依赖：

packaging>presto-plugin</packaging>     <!--设置presto版本--> <properties>     <presto.verison>0.208</presto.verison> </properties>   <dependencies>     <!-- Presto SPI -->     <dependency>         <groupId>com.facebook.presto</groupId>         <artifactId>presto-spi</artifactId>         <version>${presto.verison}</version>         <scope>provided</scope>     </dependency>       <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->     <dependency>         <groupId>com.google.guava</groupId>         <artifactId>guava</artifactId>         <version>11.0.2</version>     </dependency> </dependencies>