Explain EXPLAIN QUERY TREE (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Function transform (children 1)
      ExpressionList (children 4)
       Identifier number
       Literal Array_[UInt64_2, UInt64_4, UInt64_6]
       Literal Array_[\'google\', \'censor.net\', \'yahoo\']
       Literal \'other\'
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier system.numbers
    Literal UInt64_10
