core/src/main/java/com/orientechnologies/orient/core/sql/executor/OSelectExecutionPlanner.java
private boolean isFromClusters(ORid rid, Set<String> filterClusters, ODatabase database) {
    if (filterClusters == null) {
      throw new IllegalArgumentException();
    }
    String clusterName = database.getClusterNameById(rid.getCluster().getValue().intValue());
    return filterClusters.contains(clusterName);
  }
private boolean isFromClusters(ORid rid, Set<String> filterClusters, ODatabase database) {
    if (filterClusters == null) {
      throw new IllegalArgumentException();
    }
    String clusterName = database.getClusterNameById(rid.getCluster().getValue().intValue());
    return filterClusters.contains(clusterName);
  }
checks if this RID is from one of these clusters

@param rid
@param filterClusters
@param database

@return