array(5) {
  ["pa_materiales"]=>
  object(WC_Product_Attribute)#39245 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(1)
      ["name"]=>
      string(13) "pa_materiales"
      ["options"]=>
      array(1) {
        [0]=>
        int(86)
      }
      ["position"]=>
      int(0)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["pa_color"]=>
  object(WC_Product_Attribute)#39284 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(3)
      ["name"]=>
      string(8) "pa_color"
      ["options"]=>
      array(1) {
        [0]=>
        int(74)
      }
      ["position"]=>
      int(1)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["pa_marca"]=>
  object(WC_Product_Attribute)#39239 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(4)
      ["name"]=>
      string(8) "pa_marca"
      ["options"]=>
      array(1) {
        [0]=>
        int(97)
      }
      ["position"]=>
      int(2)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["largo-cuchara-cm"]=>
  object(WC_Product_Attribute)#39285 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(0)
      ["name"]=>
      string(18) "Largo cuchara (cm)"
      ["options"]=>
      array(1) {
        [0]=>
        string(5) "17.30"
      }
      ["position"]=>
      int(3)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
  ["largo-tenedor-cm"]=>
  object(WC_Product_Attribute)#39281 (1) {
    ["data":protected]=>
    array(6) {
      ["id"]=>
      int(0)
      ["name"]=>
      string(18) "Largo tenedor (cm)"
      ["options"]=>
      array(1) {
        [0]=>
        string(5) "17.50"
      }
      ["position"]=>
      int(4)
      ["visible"]=>
      bool(true)
      ["variation"]=>
      bool(true)
    }
  }
}

-----NULL

xxxxstring(13) "pa_materiales" bool(true)

xxxxstring(8) "pa_color" bool(true)

xxxxstring(8) "pa_marca" bool(true)

xxxxstring(18) "Largo cuchara (cm)" bool(false)

xxxxstring(18) "Largo tenedor (cm)" bool(false)