(size)
return [
      ((0., -size[1], 0.), (-1, 0, 0, 0, 0, 1)),
      ((0., size[1], 0.), (1, 0, 0, 0, 0, 1)),
      ((-size[0], 0., 0.), (0, 1, 0, 0, 0, 1)),
      ((size[0], 0., 0.), (0, -1, 0, 0, 0, 1)),
  ]
Infers position and size of bounding walls given pitch size.

  Walls are placed around `ground_geom` that represents the pitch. Note that
  the ball cannot travel beyond `field` but walkers can walk outside of the
  `field` but not the surrounding walls.

  Args:
    size: a tuple of (length, width) of the pitch.

  Returns:
    a list of 4 tuples, each representing the position and xyaxes of a wall
    plane. In order, walls are placed along x-negative, x-positive, y-negative,
    y-positive relative the center of the pitch.
Infers position and size of bounding walls given pitch size.
Infers position and size of bounding walls given pitch size .
def _wall_pos_xyaxes(size):
  """Infers position and size of bounding walls given pitch size.

  Walls are placed around `ground_geom` that represents the pitch. Note that
  the ball cannot travel beyond `field` but walkers can walk outside of the
  `field` but not the surrounding walls.

  Args:
    size: a tuple of (length, width) of the pitch.

  Returns:
    a list of 4 tuples, each representing the position and xyaxes of a wall
    plane. In order, walls are placed along x-negative, x-positive, y-negative,
    y-positive relative the center of the pitch.
  """
  return [
      ((0., -size[1], 0.), (-1, 0, 0, 0, 0, 1)),
      ((0., size[1], 0.), (1, 0, 0, 0, 0, 1)),
      ((-size[0], 0., 0.), (0, 1, 0, 0, 0, 1)),
      ((size[0], 0., 0.), (0, -1, 0, 0, 0, 1)),
  ]
def _wall_pos_xyaxes ( size ) : return [ ( ( 0. , - size [ 1 ] , 0. ) , ( - 1 , 0 , 0 , 0 , 0 , 1 ) ) , ( ( 0. , size [ 1 ] , 0. ) , ( 1 , 0 , 0 , 0 , 0 , 1 ) ) , ( ( - size [ 0 ] , 0. , 0. ) , ( 0 , 1 , 0 , 0 , 0 , 1 ) ) , ( ( size [ 0 ] , 0. , 0. ) , ( 0 , - 1 , 0 , 0 , 0 , 1 ) ) , ]