new_contents: from http.client import OK, NOT_FOUND
  import pytest
  from unittest.mock import patch
  
  from openfisca_core.entities import build_entity
  from openfisca_core.parameters import ParameterNode
  from openfisca_core.periods import MONTH, ETERNITY
  from openfisca_core.taxbenefitsystems import TaxBenefitSystem
  from openfisca_core.variables import Variable
  
  
  from openfisca_core.entities import build_entity
  
  Household = build_entity(
      key = "household",
      plural = "households",
      label = "All the people in a family or group who live together in the same place.",
      doc = "[REMOVED FOR TEST]",
      roles = [
          {
              "key": "parent",
              "plural": "parents",
              "label": "Parents",
              "max": 2,
              "subroles": ["first_parent", "second_parent"],
              "doc": "The one or two adults in charge of the household.",
              },
          {
              "key": "child",
              "plural": "children",
              "label": "Child",
              "doc": "Other individuals living in the household.",
              },
          ],
      )
  
  Person = build_entity(
      key = "person",
      plural = "persons",
      label = "An individual. The minimal legal entity on which a legislation might be applied.",
      doc = "[REMOVED FOR TEST]",
      is_person = True,
      )
  
  @pytest.fixture(scope="module")
  def entities():
      return [Household, Person]
  
  
  @pytest.fixture()
  def test_tax_benefit_system(entities):
      tax_benefit_system = TaxBenefitSystem(entities)
  
      # At least one ParameterNode must be defined, or else `openfisca_web_api.app.create_app()` will fail
      tax_benefit_system.parameters = ParameterNode(name="mockParameterNode", 
                                                    data={'amount': {'values': {
                                                                      "2015-01-01": {'value': 550},
                                                                      "2016-01-01": {'value': 600}
                                                                   }}
                                                          })
      
      # At least one Variable must be defined, or else `openfisca_web_api.app.create_app()` will fail
      class initial_variable(Variable):
          value_type = float
          entity = Person
          definition_period = MONTH
          label = "Basic income provided to adults"
          reference = "https://law.gov.example/basic_income"  # Always use the most official source
  
      tax_benefit_system.add_variable(initial_variable)
  
      return tax_benefit_system
subject: Add a minimal TaxBenefitSystem Fixture in tests/web_api/conftest.py - this minimal TaxBenefitSystem has the same Entities as the `openfisca_country_template` - it one mock Parameter and one mock Variable