SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function toFloat64OrZero (children 1)
     ExpressionList (children 1)
      Literal \'123.456a\'
    Function toFloat64OrZero (children 1)
     ExpressionList (children 1)
      Literal \'456.789\'
