code: def set(self, key, value):
      if (
          self._pclass_evolver_data.get(key, _MISSING_VALUE)
          is not value
      ):
          self._pclass_evolver_data[key] = value
          self._factory_fields.add(key)
          self._pclass_evolver_data_is_dirty = True
  
      return self
  
imports: from pyrsistent._checked_types import InvariantException, CheckedType, _restore_pickle, store_invariants
  from pyrsistent._field_common import set_fields, check_type, is_field_ignore_extra_complaint, PFIELD_NO_INITIAL, serialize, check_global_invariants
  from pyrsistent._transformations import transform
label_desc: Use image node_id 3 for calling the _PClassEvolver obj's underlying member method code with example usage: obj.set(key, value) and returns: self