new_contents: import pytest
  from plenum.common.types import Primary
  from collections import OrderedDict
  from plenum.common.messages.fields import NonNegativeNumberField, \
      LedgerIdField, MerkleRootField, IterableField, NonEmptyStringField, \
      TimestampField, HexField
  
  EXPECTED_ORDERED_FIELDS = OrderedDict([
      ("name", NonEmptyStringField),
      ("instId", NonNegativeNumberField),
      ("viewNo", NonNegativeNumberField),
      ("ordSeqNo", NonNegativeNumberField),
  ])
  
  
  def test_hash_expected_type():
      assert Primary.typename == "PRIMARY"
  
  
  def test_has_expected_fields():
      actual_field_names = OrderedDict(Primary.schema).keys()
      assert actual_field_names == EXPECTED_ORDERED_FIELDS.keys()
  
  
  def test_has_expected_validators():
      schema = dict(Primary.schema)
      for field, validator in EXPECTED_ORDERED_FIELDS.items():
          assert isinstance(schema[field], validator)
  
subject: add test for Primary message