docs: def initialize(g, app):
      """
      If postgresql url is defined in configuration params a
      scoped session will be created
      """
      if 'DATABASES' in app.config and 'POSTGRESQL' in app.config['DATABASES']:
          # Database connection established for console commands
          for k, v in app.config['DATABASES']['POSTGRESQL'].items():
              init_db_conn(k, v)
  
          if 'test' not in sys.argv:
              # Establish a new connection every request
              @app.before_request
              def before_request():
                  """
                  Assign postgresql connection pool to the global
                  flask object at the beginning of every request
                  """
                  # inject stack context if not testing
                  from flask import _app_ctx_stack
                  for k, v in app.config['DATABASES']['POSTGRESQL'].items():
                      init_db_conn(k, v, scopefunc=_app_ctx_stack)
                  g.postgresql_pool = pool
  
              # avoid to close connections if testing
              @app.teardown_request
              def teardown_request(exception):
                  """
                  Releasing connection after finish request, not required in unit
                  testing
                  """
                  pool = getattr(g, 'postgresql_pool', None)
                  if pool is not None:
                      for k, v in pool.connections.items():
                          v.session.remove()
          else:
              @app.before_request
              def before_request():
                  """
                  Assign postgresql connection pool to the global
                  flask object at the beginning of every request
                  """
                  for k, v in app.config['DATABASES']['POSTGRESQL'].items():
                      init_db_conn(k, v)
                  g.postgresql_pool = pool