code: def tube_locations():
      """
      Return an (n, 2) array of selected London Tube locations in Ordnance
      Survey GB coordinates.
  
      Source: https://www.doogal.co.uk/london_stations.php
  
      """
      return np.array(
          [
              [531738.0, 180890.0],
              [532379.0, 179734.0],
              [531096.0, 181642.0],
              [530234.0, 180492.0],
              [531688.0, 181150.0],
              [530242.0, 180982.0],
              [531940.0, 179144.0],
              [530406.0, 180380.0],
              [529012.0, 180283.0],
              [530553.0, 181488.0],
              [531165.0, 179489.0],
              [529987.0, 180812.0],
              [532347.0, 180962.0],
              [529102.0, 181227.0],
              [529612.0, 180625.0],
              [531566.0, 180025.0],
              [529629.0, 179503.0],
              [532105.0, 181261.0],
              [530995.0, 180810.0],
              [529774.0, 181354.0],
              [528941.0, 179131.0],
              [531050.0, 179933.0],
              [530240.0, 179718.0],
          ]
      )
  
imports: from matplotlib.path import Path
  import matplotlib.pyplot
  import numpy
  import cartopy.crs
  from cartopy.io.img_tiles import OSM
label_desc: Use image node_id 1 for calling a global function with example usage: tube_locations() and returns: np