docs: def write(
          unparser, nodes, output_stream, sourcemap_stream=None,
          sourcemap_normalize_mappings=True,
          sourcemap_normalize_paths=True,
          source_mapping_url=NotImplemented):
      """
      Write out the node using the unparser into an output stream, and
      optionally the sourcemap using the sourcemap stream.
  
      Ideally, file objects should be passed to the *_stream arguments, so
      that the name resolution built into the sourcemap builder function
      will be used.  Also, if these file objects are opened using absolute
      path arguments, enabling the sourcemap_normalize_paths flag will
      have all paths normalized to their relative form.
  
      If the provided streams are not anchored on the filesystem, or that
      the provide node was generated from a string or in-memory stream,
      the generation of the sourcemap should be done using the lower level
      `write` function provided by the sourcemap module, which this method
      wraps.  Alternatively, the top level node should have its sourcepath
      set to path that this node originated from.
  
      Arguments
  
      unparser
          An unparser instance.
      nodes
          The Node or list of Nodes to stream to the output stream with
          the unparser.
      output_stream
          Either a stream object or a callable that produces one.  The
          stream object to write to; its 'write' method will be invoked.
  
          If a callable was provided, the 'close' method on its return
          value will be called to close the stream.
      sourcemap_stream
          If one is provided, the sourcemap will be written out to it.
          Like output_stream, it could also be a callable and be handled
          in the same manner.
  
          If this argument is the same as output_stream (note: the return
          value of any callables are not compared), the stream object that
          is the same as the output_stream will be used for writing out
          the source map, and the source map will instead be encoded as a
          'data:application/json;base64,' URL.
      sourcemap_normalize_mappings
          Flag for the normalization of the sourcemap mappings; Defaults
          to True to enable a reduction in output size.
      sourcemap_normalize_paths
          If set to true, all absolute paths will be converted to the
          relative form when the sourcemap is generated, if all paths
          provided are in the absolute form.
  
          Defaults to True to enable a reduction in output size.
      source_mapping_url
          If unspecified, the default derived path will be written as a
          sourceMappingURL comment into the output stream.  If explicitly
          specified with a value, that will be written instead.  Set to
          None to disable this.
      """
  
      closer = []
  
      def get_stream(stream):
          if callable(stream):
              result = stream()
              closer.append(result.close)
          else:
              result = stream
          return result
  
      def cleanup():
          for close in reversed(closer):
              close()
  
      chunks = None
      if isinstance(nodes, Node):
          chunks = unparser(nodes)
      elif isinstance(nodes, Iterable):
          raw = [unparser(node) for node in nodes if isinstance(node, Node)]
          if raw:
              chunks = chain(*raw)
  
      if not chunks:
          raise TypeError('must either provide a Node or list containing Nodes')
  
      try:
          out_s = get_stream(output_stream)
          sourcemap_stream = (
              out_s if sourcemap_stream is output_stream else sourcemap_stream)
          mappings, sources, names = sourcemap.write(
              chunks, out_s, normalize=sourcemap_normalize_mappings)
          if sourcemap_stream:
              sourcemap_stream = get_stream(sourcemap_stream)
              sourcemap.write_sourcemap(
                  mappings, sources, names, out_s, sourcemap_stream,
                  normalize_paths=sourcemap_normalize_paths,
                  source_mapping_url=source_mapping_url,
              )
      finally:
          cleanup()