code: function fromStream(stream, opts) {
    opts = opts || {}
    var out = through()
  
    function ondata(res) {
      try {
        var svg = flamegraph(res.toString().split('\n'), opts)
        out.write(svg)
      } catch (err) {
        out.emit('error', err)
      }
    }
  
    // Once memory becomes an issue we need to make this truly streaming
    stream.pipe(concatStream(ondata))
    return out
  }
docs: Converts a stream of call graph lines into an svg document.
  Not truly streaming, concats all lines before processing.
  
  **Example**:
  
  ```js
  var fromStream = require('flamegraph/from-stream')
  fromStream(process.stdin, opts).pipe(process.stdout)
  ```
  
  @name flamegraph::fromStream
  @function
  @param {ReadableStream} stream that will emit the call graph lines to be parsed
  @param {Object} opts same as `flamegraph`
  @return {ReadableStream} stream that emits the lines of generated svg