SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function proportionsZTest (children 1)
     ExpressionList (children 6)
      Identifier sx
      Identifier sy
      Identifier tx
      Identifier ty
      Literal Float64_0.95
      Literal \'unpooled\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier proportions_ztest