SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier id
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab
   Function hasAnyTokens (children 1)
    ExpressionList (children 2)
     Identifier col_str
     Literal Array_[\'b\']
