docs: def graph_from_polygon(polygon, network_type='all_private', simplify=True,
                         retain_all=False, truncate_by_edge=False, name='unnamed',
                         timeout=180, memory=None,
                         max_query_area_size=50*1000*50*1000,
                         clean_periphery=True, infrastructure='way["highway"]',
                         custom_filter=None):
      """
      Create a networkx graph from OSM data within the spatial boundaries of the
      passed-in shapely polygon.
  
      Parameters
      ----------
      polygon : shapely Polygon or MultiPolygon
          the shape to get network data within. coordinates should be in units of
          latitude-longitude degrees.
      network_type : string
          what type of street network to get
      simplify : bool
          if true, simplify the graph topology
      retain_all : bool
          if True, return the entire graph even if it is not connected
      truncate_by_edge : bool
          if True retain node if it's outside bbox but at least one of node's
          neighbors are within bbox
      name : string
          the name of the graph
      timeout : int
          the timeout interval for requests and to pass to API
      memory : int
          server memory allocation size for the query, in bytes. If none, server
          will use its default allocation size
      max_query_area_size : float
          max size for any part of the geometry, in square degrees: any polygon
          bigger will get divided up for multiple queries to API
      clean_periphery : bool
          if True (and simplify=True), buffer 0.5km to get a graph larger than
          requested, then simplify, then truncate it to requested spatial extent
      infrastructure : string
          download infrastructure of given type (default is streets
          (ie, 'way["highway"]') but other infrastructures may be selected
          like power grids (ie, 'way["power"~"line"]'))
      custom_filter : string
          a custom network filter to be used instead of the network_type presets
  
      Returns
      -------
      networkx multidigraph
      """
  
      # verify that the geometry is valid and is a shapely Polygon/MultiPolygon
      # before proceeding
      if not polygon.is_valid:
          raise TypeError('Shape does not have a valid geometry')
      if not isinstance(polygon, (Polygon, MultiPolygon)):
          raise TypeError('Geometry must be a shapely Polygon or MultiPolygon. If you requested '
                           'graph from place name or address, make sure your query resolves to a '
                           'Polygon or MultiPolygon, and not some other geometry, like a Point. '
                           'See OSMnx documentation for details.')
  
      if clean_periphery and simplify:
          # create a new buffered polygon 0.5km around the desired one
          buffer_dist = 500
          polygon_utm, crs_utm = project_geometry(geometry=polygon)
          polygon_proj_buff = polygon_utm.buffer(buffer_dist)
          polygon_buffered, _ = project_geometry(geometry=polygon_proj_buff, crs=crs_utm, to_latlong=True)
  
          # get the network data from OSM,  create the buffered graph, then
          # truncate it to the buffered polygon
          response_jsons = osm_net_download(polygon=polygon_buffered, network_type=network_type,
                                            timeout=timeout, memory=memory,
                                            max_query_area_size=max_query_area_size,
                                            infrastructure=infrastructure, custom_filter=custom_filter)
          G_buffered = create_graph(response_jsons, name=name, retain_all=True,
                                    bidirectional=network_type in settings.bidirectional_network_types)
          G_buffered = truncate_graph_polygon(G_buffered, polygon_buffered, retain_all=True, truncate_by_edge=truncate_by_edge)
  
          # simplify the graph topology
          G_buffered = simplify_graph(G_buffered)
  
          # truncate graph by polygon to return the graph within the polygon that
          # caller wants. don't simplify again - this allows us to retain
          # intersections along the street that may now only connect 2 street
          # segments in the network, but in reality also connect to an
          # intersection just outside the polygon
          G = truncate_graph_polygon(G_buffered, polygon, retain_all=retain_all, truncate_by_edge=truncate_by_edge)
  
          # count how many street segments in buffered graph emanate from each
          # intersection in un-buffered graph, to retain true counts for each
          # intersection, even if some of its neighbors are outside the polygon
          G.graph['streets_per_node'] = count_streets_per_node(G_buffered, nodes=G.nodes())
  
      else:
          # download a list of API responses for the polygon/multipolygon
          response_jsons = osm_net_download(polygon=polygon, network_type=network_type,
                                            timeout=timeout, memory=memory,
                                            max_query_area_size=max_query_area_size,
                                            infrastructure=infrastructure, custom_filter=custom_filter)
  
          # create the graph from the downloaded data
          G = create_graph(response_jsons, name=name, retain_all=True,
                           bidirectional=network_type in settings.bidirectional_network_types)
  
          # truncate the graph to the extent of the polygon
          G = truncate_graph_polygon(G, polygon, retain_all=retain_all, truncate_by_edge=truncate_by_edge)
  
          # simplify the graph topology as the last step. don't truncate after
          # simplifying or you may have simplified out to an endpoint beyond the
          # truncation distance, in which case you will then strip out your entire
          # edge
          if simplify:
              G = simplify_graph(G)
  
      log('graph_from_polygon() returning graph with {:,} nodes and {:,} edges'.format(len(list(G.nodes())), len(list(G.edges()))))
      return G