@Override
  public <R, C> R accept(PlanVisitor<R, C> visitor, C context) {
    return visitor.visitSeriesSchemaFetchScan(this, context);
  }
This class defines the scan task of schema fetcher.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/plan/node/metadata/read/SeriesSchemaFetchScanNode.java