code: def test_flat(setup):
      data = np.random.rand(10, 20)
      a = tensor(data, chunk_size=4)
      fl = a.flat
      fl[1:10] = 10
      b = fl[10:20]
      b[0:4] = 20
  
      npa = data.copy()
      npfl = npa.flat
      npfl[1:10] = 10
      npb = npfl[10:20]
      npb[0:4] = 20
  
      np.testing.assert_array_equal(b.execute(), npb)
      np.testing.assert_array_equal(a.execute(), npa)
  
file_path: mars/mars/tensor/tests/test_core_execution.py
imports: import numpy
  from ..None import ones, add, swapaxes, moveaxis, atleast_1d, atleast_2d, atleast_3d, squeeze, tensor
label_desc: Use image node_id 14 for calling a global function with example usage: test_flat(setup) without return types