code: def test_pauli_word_prefactor(op, true_prefactor):
      """Test that we can accurately determine the prefactor"""
      assert pauli_word_prefactor(op) == true_prefactor
  
imports: import pytest
  import pennylane
  from pennylane.pauli import pauli_word_prefactor
label_desc: Use image node_id 1 for calling a global function with example usage: test_pauli_word_prefactor(op, true_prefactor) without return types