SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Function map (alias m) (children 1)
     ExpressionList (children 4)
      Literal \'aa\'
      Literal UInt64_4
      Literal \'bb\'
      Literal UInt64_5
    Function mapKeys (children 1)
     ExpressionList (children 1)
      Identifier m
    Function mapValues (children 1)
     ExpressionList (children 1)
      Identifier m