code: def create_group(self, name, overwrite=False):
          
  
          return self._write_op(self._create_group_nosync, name, overwrite=overwrite)
docs: Create a sub-group.
  
          Parameters
          ----------
          name : string
              Group name.
          overwrite : bool, optional
              If True, overwrite any existing array with the given name.
  
          Returns
          -------
          g : zarr.hierarchy.Group
  
          Examples
          --------
          >>> import zarr
          >>> g1 = zarr.group()
          >>> g2 = g1.create_group('foo')
          >>> g3 = g1.create_group('bar')
          >>> g4 = g1.create_group('baz/quux')