class_docstr: Unittests for the dot function when ``pauli=False``.
docstr: test that the `dot` function groups coefficients with different signs.
docstr_tok: ["test","that","the","`","dot","`","function","groups","coefficients","with","different","signs","."]
code: def test_dot_groups_coeffs_with_different_sign(self):
      """test that the `dot` function groups coefficients with different signs."""
      cs = [4, -4, 4]
      result = qml.dot(
          coeffs=cs, ops=[qml.PauliX(0), qml.PauliX(1), qml.PauliX(2)]
      )
      assert isinstance(result, SProd)
      assert result.scalar == 4
      for op, c in zip(result.base, cs):
          if c == -4:
              assert isinstance(op, SProd)
              assert op.scalar == -1
          else:
              assert isinstance(op, qml.PauliX)
  
imports: import pytest
  import pennylane
  from pennylane.ops import Hamiltonian, Prod, SProd, Sum
  from pennylane.pauli.pauli_arithmetic import PauliSentence
label_desc: Use image node_id 5 for calling the TestDotSum obj's underlying member method code with example usage: obj.test_dot_groups_coeffs_with_different_sign() without return types