code: def _encode(
      src: Tensor,
      sample_rate: int,
      effect: str,
      muxer: str,
      encoder: Optional[str],
      codec_config: Optional[CodecConfig],
  ):
      buffer = io.BytesIO()
      writer = StreamWriter(buffer, format=muxer)
      writer.add_audio_stream(
          num_channels=src.size(1),
          sample_rate=sample_rate,
          format=_get_sample_fmt(src.dtype),
          encoder=encoder,
          filter_desc=effect,
          codec_config=codec_config,
      )
      with writer.open():
          writer.write_audio_chunk(0, src)
      buffer.seek(0)
      return buffer
  
imports: import io
  from typing import Iterator, List, Optional
  import torch
  from torch import Tensor
  from torio.io._streaming_media_decoder import _get_afilter_desc, StreamingMediaDecoder
  from torio.io._streaming_media_encoder import CodecConfig, StreamingMediaEncoder
label_desc: Use image node_id 2 for calling a global function with example usage: _encode(src, sample_rate, effect, muxer, encoder, codec_config) and returns: buffer