How to use the min-dash.isDefined function in min-dash

if (scaleConfig !== true) {

    if (scaleConfig === false) {
      minScale = 1;
      maxScale = 1;
    } else {
      minScale = scaleConfig.min;
      maxScale = scaleConfig.max;
    }

    if (isDefined(minScale) && zoom < minScale) {
      scale = minScale;
    }

    if (isDefined(maxScale) && zoom > maxScale) {
      scale = maxScale;
    }

  }

  setTransform(container, 'scale(' + scale + ')');
};

sourceProperty = sourceElement.get(propertyName);
    }

    var copiedProperty = self.copyProperty(sourceProperty, targetElement, propertyName);

    var canSetProperty = self._eventBus.fire('moddleCopy.canSetCopiedProperty', {
      parent: parent,
      property: copiedProperty,
      propertyName: propertyName
    });

    if (canSetProperty === false) {
      return;
    }

    if (isDefined(copiedProperty)) {
      targetElement.set(propertyName, copiedProperty);
    }
  });

Overlays.prototype._updateOverlayVisibilty = function(overlay, viewbox) {
  var show = overlay.show,
      minZoom = show && show.minZoom,
      maxZoom = show && show.maxZoom,
      htmlContainer = overlay.htmlContainer,
      visible = true;

  if (show) {
    if (
      (isDefined(minZoom) && minZoom > viewbox.scale) ||
      (isDefined(maxZoom) && maxZoom < viewbox.scale)
    ) {
      visible = false;
    }

    setVisible(htmlContainer, visible);
  }

  this._updateOverlayScale(overlay, viewbox);
};

export default function PopupMenu(config, eventBus, canvas) {

  var scale = isDefined(config && config.scale) ? config.scale : {
    min: 1,
    max: 1.5
  };

  this._config = {
    scale: scale
  };

  this._eventBus = eventBus;
  this._canvas = canvas;
  this._providers = {};
  this._current = {};
}

function isContainer(o) {
  return (
    isDefined(o) &&
    isObject(o)
  );
}

if (shouldScale !== true) {

    if (shouldScale === false) {
      minScale = 1;
      maxScale = 1;
    } else {
      minScale = shouldScale.min;
      maxScale = shouldScale.max;
    }

    if (isDefined(minScale) && viewbox.scale < minScale) {
      scale = (1 / viewbox.scale || 1) * minScale;
    }

    if (isDefined(maxScale) && viewbox.scale > maxScale) {
      scale = (1 / viewbox.scale || 1) * maxScale;
    }
  }

  if (isDefined(scale)) {
    transform = 'scale(' + scale + ',' + scale + ')';
  }

  setTransform(htmlContainer, transform);
};

Overlays.prototype._updateOverlayVisibilty = function(overlay, viewbox) {
  var show = overlay.show,
      minZoom = show && show.minZoom,
      maxZoom = show && show.maxZoom,
      htmlContainer = overlay.htmlContainer,
      visible = true;

  if (show) {
    if (
      (isDefined(minZoom) && minZoom > viewbox.scale) ||
      (isDefined(maxZoom) && maxZoom < viewbox.scale)
    ) {
      visible = false;
    }

    setVisible(htmlContainer, visible);
  }

  this._updateOverlayScale(overlay, viewbox);
};

maxScale,
      htmlContainer = overlay.htmlContainer;

  var scale, transform = '';

  if (shouldScale !== true) {

    if (shouldScale === false) {
      minScale = 1;
      maxScale = 1;
    } else {
      minScale = shouldScale.min;
      maxScale = shouldScale.max;
    }

    if (isDefined(minScale) && viewbox.scale < minScale) {
      scale = (1 / viewbox.scale || 1) * minScale;
    }

    if (isDefined(maxScale) && viewbox.scale > maxScale) {
      scale = (1 / viewbox.scale || 1) * maxScale;
    }
  }

  if (isDefined(scale)) {
    transform = 'scale(' + scale + ',' + scale + ')';
  }

  setTransform(htmlContainer, transform);
};

maxScale = 1;
    } else {
      minScale = shouldScale.min;
      maxScale = shouldScale.max;
    }

    if (isDefined(minScale) && viewbox.scale < minScale) {
      scale = (1 / viewbox.scale || 1) * minScale;
    }

    if (isDefined(maxScale) && viewbox.scale > maxScale) {
      scale = (1 / viewbox.scale || 1) * maxScale;
    }
  }

  if (isDefined(scale)) {
    transform = 'scale(' + scale + ',' + scale + ')';
  }

  setTransform(htmlContainer, transform);
};