class_docstr: Visits the SQL query plan to simplify sub-queries. On each visit, return a simplified node.
  
  Unlike SqlSubQueryReducerVisitor, this will re-write expressions to realize more reductions.
docstr: Apply the reducing operation to the parent select statements.
code: def _reduce_parents(
      self,
      node: SqlSelectStatementNode,
  ) -> SqlSelectStatementNode:
      """Apply the reducing operation to the parent select statements."""
      return SqlSelectStatementNode(
          description=node.description,
          select_columns=node.select_columns,
          from_source=node.from_source.accept(self),
          from_source_alias=node.from_source_alias,
          joins_descs=tuple(
              SqlJoinDescription(
                  right_source=x.right_source.accept(self),
                  right_source_alias=x.right_source_alias,
                  on_condition=x.on_condition,
                  join_type=x.join_type,
              )
              for x in node.join_descs
          ),
          group_bys=node.group_bys,
          order_bys=node.order_bys,
          where=node.where,
          limit=node.limit,
          distinct=node.distinct,
      )
  
imports: from __future__ import annotations
  import logging
  from dataclasses import dataclass
  from typing import List, Optional, Sequence, Tuple
  from metricflow.sql.optimizer.sql_query_plan_optimizer import SqlQueryPlanOptimizer
  from metricflow.sql.sql_exprs import SqlColumnAliasReferenceExpression, SqlColumnReference, SqlColumnReplacements, SqlExpressionNode, SqlExpressionTreeLineage, SqlLogicalExpression, SqlLogicalOperator
  from metricflow.sql.sql_plan import SqlJoinDescription, SqlOrderByDescription, SqlQueryPlanNode, SqlQueryPlanNodeVisitor, SqlSelectColumn, SqlSelectQueryFromClauseNode, SqlSelectStatementNode, SqlTableFromClauseNode
label_desc: Use image node_id 1 for calling the SqlRewritingSubQueryReducerVisitor obj's underlying member method code with example usage: obj._reduce_parents(node) and returns: SqlSelectStatementNode