SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function toDecimal256 (children 1)
     ExpressionList (children 2)
      Literal Float64_1234567890.1234567
      Literal UInt64_30
    Function JSONExtract (children 1)
     ExpressionList (children 2)
      Literal \'{"a":1234567890.12345678901234567890, "b":"test"}\'
      Literal \'Tuple(a Decimal(45,30), b LowCardinality(String))\'