class_docstr: Measurement process that computes the purity of the system prior to measurement.
  
  Please refer to :func:`purity` for detailed documentation.
  
  Args:
      wires (.Wires): The wires the measurement process applies to.
      id (str): custom label given to a measurement instance, can be useful for some
          applications where the instance has to be identified
code: def __init__(self, wires: Wires, id: Optional[str] = None):
      super().__init__(wires=wires, id=id)
  
file_path: pennylane/pennylane/measurements/purity.py
imports: from typing import Sequence, Optional
  import pennylane
  from pennylane.wires import Wires
  from .measurements import StateMeasurement, Purity
label_desc: Use image node_id 1 to create a new PurityMP object from inherited base classes: StateMeasurement with example: obj = PurityMP(wires, id)