class_docstr: Test the TrotterProduct class initializes correctly.
class_docstr_tok: ["Test","the","TrotterProduct","class","initializes","correctly","."]
docstr: Test that an error is raised if the input hamultonian has only 1 term.
docstr_tok: ["Test","that","an","error","is","raised","if","the","input","hamultonian","has","only","1","term","."]
code: def test_error_hamiltonian(self):
      """Test that an error is raised if the input hamultonian has only 1 term."""
      with pytest.raises(
          ValueError,
          match="There should be atleast 2 terms in the Hamiltonian.",
      ):
          qml.TrotterProduct(
              qml.Hamiltonian([1.0], [qml.PauliX(0)]),
              1.23,
              n=2,
              order=4,
          )
  
imports: import copy
  from functools import reduce
  import pytest
  import pennylane
  from pennylane import numpy
  from pennylane.math import allclose, get_interface
  from pennylane.templates.subroutines.trotter import _recursive_expression, _scalar
label_desc: Use image node_id 3 for calling the TestInitialization obj's underlying member method code with example usage: obj.test_error_hamiltonian() without return types