text: from typing import (
      Mapping,
      Optional,
  )
  
  
  def env() -> Mapping[str, Optional[str]]:
      """
      Returns a dictionary that maps environment variable names to values. The 
      values are either None or strings. String values can contain references to 
      other environment variables in the form `{FOO}` where FOO is the name of an 
      environment variable. See 
  
      https://docs.python.org/3.8/library/string.html#format-string-syntax
  
      for the concrete syntax. The references will be resolved after the 
      environment has been compiled by merging all environment.py files.
  
      Entries with a None value will be excluded from the environment. They should 
      be used to document variables without providing a default value. Other,
      usually more specific environment.py files should provide the value.
      """
      return {
          # Set variables for the `sandbox` deployment here. The sandbox can be used to
          # run integration tests against a PR and to perform CI/CD experiments.
          #
          # Only modify this file if you intend to commit those changes. To change the
          # environment with a setting that's specific to you AND the deployment, create a
          # environment.local.py right next to this file and make your changes there.
          # Settings applicable to all environments but specific to you go into
          # environment.local.py at the project root.
  
          'AZUL_DEPLOYMENT_STAGE': 'sandbox',
  
          'AZUL_CATALOGS': 'dcp2:repository/tdr:metadata/hca,'
                           'dcp2ebi:repository/tdr:metadata/hca,'
                           'dcp1:repository/dss:metadata/hca,'
                           'it2:repository/tdr:metadata/hca,'
                           'it2ebi:repository/tdr:metadata/hca,'
                           'it1:repository/dss:metadata/hca',
  
          'AZUL_DSS_ENDPOINT': 'https://dss.data.humancellatlas.org/v1',
          'AZUL_DSS_DIRECT_ACCESS': '1',
          'AZUL_DSS_DIRECT_ACCESS_ROLE': 'arn:aws:iam::109067257620:role/azul-sc',
          'AZUL_SUBSCRIBE_TO_DSS': '0',
  
          'AZUL_TDR_SOURCE': 'tdr:broad-jade-dev-data:snapshot/hca_dev_20200819___20201202',
          'AZUL_TDR_DCP2EBI_SOURCE': 'tdr:broad-jade-dev-data:snapshot/hca_dev_20201023_ebiv4___20201121',
          'AZUL_TDR_IT2EBI_SOURCE': 'tdr:broad-jade-dev-data:snapshot/hca_dev_20201023_ebiv4___20201121',
          'AZUL_TDR_SERVICE_URL': 'https://jade.datarepo-dev.broadinstitute.org',
          'AZUL_SAM_SERVICE_URL': 'https://sam.dsde-dev.broadinstitute.org',
  
          # The sandbox deployment uses a subdomain of the `dev` deployment's domain.
          #
          'AZUL_DOMAIN_NAME': 'dev.singlecell.gi.ucsc.edu',
          'AZUL_SUBDOMAIN_TEMPLATE': '*.{AZUL_DEPLOYMENT_STAGE}',
  
          'AZUL_DRS_DOMAIN_NAME': 'drs.sandbox.dev.singlecell.gi.ucsc.edu',
  
          'AZUL_URL_REDIRECT_BASE_DOMAIN_NAME': 'dev.url.singlecell.gi.ucsc.edu',
          'AZUL_URL_REDIRECT_FULL_DOMAIN_NAME': '{AZUL_DEPLOYMENT_STAGE}.{AZUL_URL_REDIRECT_BASE_DOMAIN_NAME}',
  
          # $0.186/h × 2 × 24h/d × 30d/mo = $267.84/mo
          'AZUL_ES_INSTANCE_TYPE': 'r5.large.elasticsearch',
          'AZUL_ES_INSTANCE_COUNT': '2',
  
          'azul_dss_query_prefix': '42',
  
          'AZUL_DEBUG': '1',
  
          'AZUL_OWNER': 'hannes@ucsc.edu',
  
          'AZUL_AWS_ACCOUNT_ID': '122796619775',
          'AWS_DEFAULT_REGION': 'us-east-1',
  
          'GOOGLE_PROJECT': 'human-cell-atlas-travis-test',
      }
  