@Override
  public List<PartialPath> visitBinaryExpression(
      BinaryViewExpression binaryViewExpression, Void context) {
    List<PartialPath> result = new ArrayList<>();
    List<ViewExpression> expressionList = binaryViewExpression.getChildViewExpressions();
    for (ViewExpression expression : expressionList) {
      result.addAll(this.process(expression, null));
    }
    return result;
  }
Use this visitor to find all the paths of time series used in one expression.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/view/visitor/GetSourcePathsVisitor.java