class_docstr: Tests that the template defines the correct decomposition.
docstr: Test the decomposition of the U_{1, ex}` exchange gate by asserting the prepared
  state.
docstr_tok: ["Test","the","decomposition","of","the","U_","{","1",",","ex","}","`","exchange","gate","by","asserting","the","prepared","state","."]
code: def test_decomposition_u1ex(self, init_state, exp_state, tol):
      """Test the decomposition of the U_{1, ex}` exchange gate by asserting the prepared
      state."""
  
      N = 2
      wires = range(N)
      weights = np.array([[[0.2045368, -0.6031732]]])
  
      dev = qml.device("default.qubit", wires=N)
  
      @qml.qnode(dev)
      def circuit(weights):
          qml.ParticleConservingU1(
              weights, wires, init_state=init_state
          )
          return qml.state()
  
      assert np.allclose(circuit(weights), exp_state, atol=tol)
  
imports: import pytest
  import numpy
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 4 for calling the TestDecomposition obj's underlying member method code with example usage: obj.test_decomposition_u1ex(init_state, exp_state, tol) and returns: qml