static LongArrayList appendToSkipFirst(LongArrayList orig, LongArrayList toAppend) {
    int size = orig.size() + toAppend.size() - 1;
    orig.ensureCapacity(size);
    System.arraycopy(toAppend.buffer, 1, orig.buffer, orig.size(), toAppend.size() - 1);
    orig.elementsCount = size;
    return orig;
  }
Builds a multipolygon from linestrings containing the IDs of nodes in edge segments and a node ID location
provider.
<p>
Attempts to close rings where endpoints are within {@code minGap} units apart.

@param rings     edge segment node ID sequences
@param nodeCache node location provider
@param osmId     ID of this multipolygon
@param minGap    the minimum units apart to close a linestring
@return The new multipolygon
@throws GeometryException if building the polygon fails
planetiler-core/src/main/java/com/onthegomap/planetiler/reader/osm/OsmMultipolygon.java