docs: def _auth(profile=None):
      '''
      Set up neutron credentials
      '''
      if profile:
          credentials = __salt__['config.option'](profile)
          user = credentials['keystone.user']
          password = credentials['keystone.password']
          tenant = credentials['keystone.tenant']
          auth_url = credentials['keystone.auth_url']
          region_name = credentials.get('keystone.region_name', None)
          service_type = credentials.get('keystone.service_type', 'network')
          os_auth_system = credentials.get('keystone.os_auth_system', None)
          use_keystoneauth = credentials.get('keystone.use_keystoneauth', False)
          verify = credentials.get('keystone.verify', True)
      else:
          user = __salt__['config.option']('keystone.user')
          password = __salt__['config.option']('keystone.password')
          tenant = __salt__['config.option']('keystone.tenant')
          auth_url = __salt__['config.option']('keystone.auth_url')
          region_name = __salt__['config.option']('keystone.region_name')
          service_type = __salt__['config.option']('keystone.service_type')
          os_auth_system = __salt__['config.option']('keystone.os_auth_system')
          use_keystoneauth = __salt__['config.option']('keystone.use_keystoneauth')
          verify = __salt__['config.option']('keystone.verify')
  
      if use_keystoneauth is True:
          project_domain_name = credentials['keystone.project_domain_name']
          user_domain_name = credentials['keystone.user_domain_name']
  
          kwargs = {
              'username': user,
              'password': password,
              'tenant_name': tenant,
              'auth_url': auth_url,
              'region_name': region_name,
              'service_type': service_type,
              'os_auth_plugin': os_auth_system,
              'use_keystoneauth': use_keystoneauth,
              'verify': verify,
              'project_domain_name': project_domain_name,
              'user_domain_name': user_domain_name
          }
      else:
          kwargs = {
              'username': user,
              'password': password,
              'tenant_name': tenant,
              'auth_url': auth_url,
              'region_name': region_name,
              'service_type': service_type,
              'os_auth_plugin': os_auth_system
          }
  
      return suoneu.SaltNeutron(**kwargs)