SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Literal \'0.0000000000000000001\' (alias x)
    Function toDecimal64 (children 1)
     ExpressionList (children 2)
      Identifier x
      Literal UInt64_18