code: def coverage_union(a, b, **kwargs):
      """Merges multiple polygons into one. This is an optimized version of
      union which assumes the polygons to be non-overlapping.
  
      Parameters
      ----------
      a : Geometry or array_like
      b : Geometry or array_like
      **kwargs
          See :ref:`NumPy ufunc docs <ufuncs.kwargs>` for other keyword arguments.
  
      See also
      --------
      coverage_union_all
  
      Examples
      --------
      >>> from shapely import normalize, Polygon
      >>> polygon = Polygon([(0, 0), (0, 1), (1, 1), (1, 0), (0, 0)])
      >>> normalize(coverage_union(polygon, Polygon([(1, 0), (1, 1), (2, 1), (2, 0), (1, 0)])))
      <POLYGON ((0 0, 0 1, 1 1, 2 1, 2 0, 1 0, 0 0))>
  
      Union with None returns same polygon
      >>> normalize(coverage_union(polygon, None))
      <POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))>
      """
      return coverage_union_all([a, b], **kwargs)
  
file_path: shapely/shapely/set_operations.py
imports: import numpy
  from shapely import GeometryType, lib
  from shapely.decorators import multithreading_enabled
  from shapely.errors import UnsupportedGEOSVersionError
label_desc: Use image node_id 8 for calling a global function with example usage: coverage_union(a, b) and returns: coverage_union_all