class_docstr: Tests for sparse hamiltonian observable
class_docstr_tok: ["Tests","for","sparse","hamiltonian","observable"]
docstr: Test label method returns 𝓗
docstr_tok: ["Test","label","method","returns","\ud835\udcd7"]
code: def test_label(self):
      """Test label method returns 𝓗"""
      H = qml.SparseHamiltonian(
          csr_matrix(np.array([[1, 0], [-1.5, 0]])), 1
      )
      assert H.label() == "𝓗"
  
file_path: pennylane/tests/ops/qubit/test_sparse.py
imports: import pytest
  import numpy
  from scipy.sparse import coo_matrix, csr_matrix
  import pennylane
label_desc: Use image node_id 1 for calling the TestSparse obj's underlying member method code with example usage: obj.test_label() without return types