  this.$.productQuery.ref.child(key).remove()
        }
      }

      _verifyUploadFile() {
        let file = this.$.uploadImageFile.files[0]
        if (!file.type.match(/image.*/)) {
          this.toastText = 'Invalid file format'
          this.$.toastAlert.open()
          this.$.uploadImageFile.value = null
        } else if (file.size > this.maxFileSize) {
          this.toastText = 'File size maximum is 1 MB'
          this.$.toastAlert.open()
          this.$.uploadImageFile.value = null
        