UpdateQuery  lightweight_test (children 3)
 Identifier lightweight_test
 Function in (children 1)
  ExpressionList (children 2)
   Identifier key
   Subquery (children 1)
    SelectWithUnionQuery (children 1)
     ExpressionList (children 1)
      SelectQuery (children 2)
       ExpressionList (children 1)
        Identifier key
       TablesInSelectQuery (children 1)
        TablesInSelectQueryElement (children 1)
         TableExpression (children 1)
          TableIdentifier keys
 ExpressionList (children 1)
  Assignment value (children 1)
   Literal \'UPDATED-1\'
