class_docstr: Test the label method on parametric ops
docstr: Test labelling works if variable is a string instead of a float.
code: def test_string_parameter(self):
      """Test labelling works if variable is a string instead of a float."""
  
      op1 = qml.TRX("x", wires=0)
      assert op1.label() == "TRX"
      assert op1.label(decimals=0) == "TRX\n(x)"
  
imports: import copy
  from functools import reduce
  import pytest
  import numpy
  from gate_data import TSHIFT, TCLOCK
  from pennylane import numpy
  import pennylane
  from pennylane.wires import Wires
label_desc: Use image node_id 6 for calling the TestLabel obj's underlying member method code with example usage: obj.test_string_parameter() without return types