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function allNonNullFieldsPopup(feature, layer) {
  let featureProperties = feature.properties;
  let popupHtml = "";
  for (let property in featureProperties) {
    if (featureProperties[property] !== null) {
      popupHtml += `<b>${property}:</b> ${featureProperties[property]}<br>`;
    }
  }
  layer.bindPopup(popupHtml);
}