class_docstr: Tests for purity measurements
class_docstr_tok: ["Tests","for","purity","measurements"]
docstr: Test that the return type is defined and the purity enum.
docstr_tok: ["Test","that","the","return","type","is","defined","and","the","purity","enum","."]
code: def test_return_type(self):
      """Test that the return type is defined and the purity enum."""
      m = PurityMP(wires=qml.wires.Wires((0, 1)))
      assert m.return_type is qml.measurements.Purity
  
imports: import pytest
  import numpy
  import pennylane
  from pennylane.measurements import PurityMP, Shots
label_desc: Use image node_id 1 for calling the TestPurityUnitTest obj's underlying member method code with example usage: obj.test_return_type() without return types