def METHOD_NAME(verbose=0):
  if (verbose): print('Checking flex->ref_c_grid conversions')
  a = flex.double(flex.grid((2, 3)))
  assert a.accessor() == rt.use_const_ref_c_grid_2(a)
  assert a.all() == rt.use_const_ref_c_grid_2(a).all()
  assert a.accessor().all() == rt.use_const_ref_c_grid_padded_2(a).all()
  assert a.accessor().all() == rt.use_const_ref_c_grid_padded_2(a).focus()
  a = flex.double(flex.grid((2, 3, 4)))
  assert a.accessor() == rt.use_const_ref_c_grid_3(a)
  assert a.all() == rt.use_const_ref_c_grid_3(a).all()
  assert a.accessor().all() == rt.use_const_ref_c_grid_padded_3(a).all()
  assert a.accessor().all() == rt.use_const_ref_c_grid_padded_3(a).focus()
  a = flex.double(flex.grid((2, 3, 5)).set_focus((2, 3, 4)))
  assert a.accessor().all() == rt.use_const_ref_c_grid_padded_3(a).all()
  assert a.accessor().focus() == rt.use_const_ref_c_grid_padded_3(a).focus()
  assert a.is_0_based()
  assert a.is_padded()
  b = flex.double(flex.grid((1,2,3), (4,6,8)))
  assert not b.is_0_based()
  assert not b.is_padded()
  for c in [a,b]:
    try: rt.use_const_ref_c_grid_3(c)
    except KeyboardInterrupt: raise
    except Exception as e:
      assert str(e).startswith("Python argument types in")
    else: raise RuntimeError("Boost.Python.ArgumentError expected.")
  if (verbose): print('OK')