public Feature setBufferPixelOverrides(ZoomFunction<Number> buffer) {
      bufferPixelOverrides = buffer;
      return this;
    }
Sets zoom-specific overrides to the number of pixels of detail to render outside the visible tile boundary.
<p>
If {@code buffer} is {@code null} or returns {@code null}, the buffer pixels will default to
{@link #setBufferPixels(double)}.
planetiler-core/src/main/java/com/onthegomap/planetiler/FeatureCollector.java