Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     QualifiedAsterisk (children 2)
      Identifier a
      ColumnsTransformerList (children 2)
       ColumnsApplyTransformer
       ColumnsApplyTransformer
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier columns_transformers (alias a)
