array(5) {
  ["pa_color"]=>
  object(WC_Product_Attribute)#40851 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(3)
      ["name"]=>
      string(8) "pa_color"
      ["options"]=>
      array(1) {
        [0]=>
        int(77)
      }
      ["position"]=>
      int(0)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["pa_marca"]=>
  object(WC_Product_Attribute)#41079 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(4)
      ["name"]=>
      string(8) "pa_marca"
      ["options"]=>
      array(1) {
        [0]=>
        int(139)
      }
      ["position"]=>
      int(1)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["pa_materiales"]=>
  object(WC_Product_Attribute)#41092 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(1)
      ["name"]=>
      string(13) "pa_materiales"
      ["options"]=>
      array(1) {
        [0]=>
        int(86)
      }
      ["position"]=>
      int(2)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["pa_temperatura-recomenda"]=>
  object(WC_Product_Attribute)#41096 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(7)
      ["name"]=>
      string(24) "pa_temperatura-recomenda"
      ["options"]=>
      array(1) {
        [0]=>
        int(93)
      }
      ["position"]=>
      int(3)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["tamano-largo-ancho-alto-cm"]=>
  object(WC_Product_Attribute)#41076 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(0)
      ["name"]=>
      string(30) "Tamaño (Largo-Ancho-Alto, cm)"
      ["options"]=>
      array(1) {
        [0]=>
        string(19) "19.0 x 16.16 x 6.89"
      }
      ["position"]=>
      int(4)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
}

-----NULL

xxxxstring(8) "pa_color" bool(true)

xxxxstring(8) "pa_marca" bool(true)

xxxxstring(13) "pa_materiales" bool(true)

xxxxstring(24) "pa_temperatura-recomenda" bool(true)

xxxxstring(30) "Tamaño (Largo-Ancho-Alto, cm)" bool(false)