EmptyPartError in get_contour when chunked

[SorooshMani-NOAA]

I'm still getting the "can't create multiline string with empty component and I'm not sure why. I updated ocsmesh main branch using pip install and adding both code snippets for the hold and the matplotlib package. Here is what the error code says:

Traceback (most recent call last):
  File "/mnt/projects/hpc/mattwig/grid/ocsmesh/usace_dem.py", line 123, in <module>
    hfun_r1.add_contour(level=ref_r1+50, expansion_rate=0.05, target_size=150)
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/ocsmesh/features/constraint.py", line 403, in wrapped
    rv = method(obj, *args, **kwargs)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/ocsmesh/hfun/raster.py", line 1022, in add_contour
    _contours = self.raster.get_contour(_level)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/ocsmesh/raster.py", line 1371, in get_contour
    return self._get_raster_contour_feathered(level, iter_windows)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/ocsmesh/raster.py", line 1497, in _get_raster_contour_feathered
    results = self._get_raster_contour_feathered_internal(
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/ocsmesh/raster.py", line 1559, in _get_raster_contour_feathered_internal
    features = ops.linemerge(features)
               ^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/shapely/ops.py", line 108, in linemerge
    source = MultiLineString([ls.coords for ls in lines])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/mattwig/miniconda3/envs/ocsmesh/lib/python3.11/site-packages/shapely/geometry/multilinestring.py", line 52, in __new__
    raise EmptyPartError(
shapely.errors.EmptyPartError: Can't create MultiLineString with empty component

Originally posted by @melissamattwig in #127 (reply in thread)