public void configure(
      Configuration conf, PartitionExpressionProxy expressionProxy, MetadataStore store) {
    this.conf = conf;
    this.expressionProxy = expressionProxy;
    this.store = store;
    this.fileFormatProxy = expressionProxy.getFileFormatProxy(getType());
  }
Configures the handler. Called once before use.
@param conf Config.
@param expressionProxy Expression proxy to access ql stuff.
@param store Storage interface to manipulate the metadata.
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/FileMetadataHandler.java