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.
code: def _find_matching_table_alias(
      node: SqlSelectStatementNode, column_alias: str
  ) -> Optional[str]:
      for select_column in node.select_columns:
          if select_column.column_alias == column_alias:
              column_reference_expr = (
                  select_column.expr.as_column_reference_expression
              )
              if column_reference_expr:
                  return column_reference_expr.col_ref.table_alias
      return None
  
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 8 for calling the SqlRewritingSubQueryReducerVisitor obj's underlying member method code with example usage: obj._find_matching_table_alias(node, column_alias) and returns: None, column_reference_expr