code: def s3_cache_readonly(self):
          
          return coerce_boolean(self.get(property_name='s3_cache_readonly',
                                         environment_variable='PIP_ACCEL_S3_READONLY',
                                         configuration_option='s3-readonly',
                                         default=False))
docs: Whether the Amazon S3 bucket is considered read only.
  
          If this is :data:`True` then the Amazon S3 bucket will only be used for
          :class:`~pip_accel.caches.s3.S3CacheBackend.get()` operations (all
          :class:`~pip_accel.caches.s3.S3CacheBackend.put()` operations will
          be disabled).
  
          - Environment variable: ``$PIP_ACCEL_S3_READONLY`` (refer to
            :func:`~humanfriendly.coerce_boolean()` for details on how the
            value of the environment variable is interpreted)
          - Configuration option: ``s3-readonly`` (also parsed using
            :func:`~humanfriendly.coerce_boolean()`)
          - Default: :data:`False`
  
          For details please refer to the :mod:`pip_accel.caches.s3` module.