private static ExpressionRewriter createRewrite(Metadata metadata) {
    return (expression, context) ->
        ExpressionTreeRewriter.rewriteWith(new Visitor(metadata), expression);
  }
Flattens and removes duplicate conjuncts or disjuncts. E.g.,

<p>a = 1 AND a = 1

<p>rewrites to:

<p>a = 1
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/iterative/rule/RemoveDuplicateConditions.java