code: function stream (env) {
      let filter = parseFilter(env)
  
      filter.promise
        .then(data => {
          env.logger.log('Sass sources successfully parsed.')
          env.data = data
          onEmpty(data, env)
        })
  
      /**
       * Returned Promise await the full sequence,
       * instead of just the parsing step.
       */
      filter.promise = new Promise((resolve, reject) => {
  
        async function documentize () {
          try {
            init(env)
            await refresh(env)
            await theme(env)
            okay(env)
            resolve()
          } catch (err) {
            reject(err)
            env.emit('error', err)
            throw err
          }
        }
  
        filter
          .on('end', documentize)
          .on('error', err => env.emit('error', err))
          .resume() // Drain.
  
      })
  
      return filter
    }
docs: Execute full SassDoc sequence from a Vinyl files stream.
  @return {Stream}
  @return {Promise} - as a property of Stream.